360 N.O.S. MP crate....need help/suggestions building up!!

[joe1978c]

Hi all. I have a 70 'Cuda 340/727/8.75. I am new at joining (but have been reading for a WHILE). Basically, I ran across one of the magnum MP 360 (300hp) and bought b/c price.  The motor has never been started, having been in a garage on an engine stand for YEARS, but spins over easily and has good compression.  I only paid $2500 for it, and it included (all new) a 670cfm holley truck avenger car (obviously too small) , MP distributor and MP hyfire box (think actually labeled as MP part but really just a MSD 6AL box), edelbrock ceramic coat shorty headers (also don't need), plugs, wires, and even a matching MP air cleaner that matches valve covers.  Obviously, I can recoup a decent amt of $ selling the parts I won't be using, especially b/c they are new.  I am confused since the 300hp and 380hp versions only seem to be a different cam and a single plane M1 intake vs. my dual plane.  Seems VERY little changes to get 80HP!!! Although, Ive also heard the 380hp version had higher compression due to pistons, but find conflicting info on this.  I would like to get the motor to 450-475+ hp.  Thoughts? ideas?  I also considered changing the heads, figuring I could also recoup some $ from the NEW magnum heads.  I was considering getting eddy perf rpm heads (unless someone could recommend a better option), bigger cam, switching the M1 dual plane intake for a single plane M1 (also considering eddy air-gap intake...anyone know which one is a better choice...I know that's a question that depends but looking for a street bruiser, not a TRUE daily driver or full race vehicle, but still be street able you know  Also, was planning to run about a 2800-3000 stahl and either 3:73 or 3:90 gear ratio.  Also, planned on running 1 3/4 long tube heads.   Sorry, I realize this is long winded but would love input ad want to make the RIGHT decision the FIRST time.  FYI: gonna build/ go back to BUILT 340 later, but figured this wouldn't be a bad option for a year or 2, since Im trying to finish my 68 GTX right now (about 80-85% done)  Thanks so much in advance. I can b reached here or ay joe1978c@yahoo.com.  I did find an older article with a similar build.
   http://www.hotrod.com/techarticles/engine/hrdp_0804_small_block_mopar_engine/viewall.html
Thanks again and all advice/suggestions will be much appreciated!!!!
-Joe-

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1968 Plymouth GTX 440/727/8.75
1970 Plymouth Cuda Shaker hood 340/727/8.75
2004 Acura 3.2TL S-Type

[Chryco Psycho]

Welcome to the site
The 360 crates do have more HP due to cam ,intake, compression .
IMO the Eddy heads are a sideways move at best , the Magnum has better heads you could switch to RHS or Airwolf heads for real flow improvements , cam profiles are  the other big gain , roller cams are factory & can be used in the magnum block but flat tappet cams can also be used , the shaft style rocker heads cannot be used as there is no provision to feed the rocker shafts . Or you could build an R3 block with W8 heads & make 600 + hp easy !

[joe1978c]

Welcome to the site
The 360 crates do have more HP due to cam ,intake, compression .
IMO the Eddy heads are a sideways move at best , the Magnum has better heads you could switch to RHS or Airwolf heads for real flow improvements , cam profiles are  the other big gain , roller cams are factory & can be used in the magnum block but flat tappet cams can also be used , the shaft style rocker heads cannot be used as there is no provision to feed the rocker shafts . Or you could build an R3 block with W8 heads & make 600 + hp easy !

Thx Chryco. I just stumbled across this new motor VERY cheap.  I plan on REALLY building my 340 in the future, but since I got this 300hp magnum motor SO cheap, w/lots of extras I can sell that I don't need (eddy ceramic headers, 670 holley truck avenger carb, etc. etc. and ALL parts BRAND new) and will leave me w/VERY little in this motor for the time being while I finish restoring the cuda AND finishing my GTX, u know.  Don't know if u looked at the link I posted, which is where the idea for eddy heads came from.  I know I need to ditch the dual plane M1 intake, the .400ish lift truck cam, etc. IYO, which route would u go to just beef up the motor a bit (nothing crazy, just 450hp or so)as far as intake (M1 single plane? eddy air gap? something else?), also what are your thoughts on cam profiles?  Do u think the stock magnum heads on the motor are fine? (not sure if that's what u meant, but hear I need to change springs at a minimum, have ported, machined for bigger valves, etc.  Do u think the magnum heads are worth doing that or do u think the costs would outweigh the benefits, and just buying RHS or Airwolf heads (which im not familiar w/honestly) are a better choice?  Thx in advance and sorry for all the questions.  This is my first w/a magnum motor, having only built LA small blocks and of course big blocks.  But I certainly appreciate the feedback.  Like everyone else, I am trying to get as much knowledge as possible first and build it ONCE!!!  LOL.  Thx again brother
-Joe-

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1968 Plymouth GTX  440/727/8.75
1970 Plymouth Cuda, Shaker, 340/727/8.75...(temporary 360 MP crate going in soon (hopefully)
2004 Acura 3.2TL S-Type

[Chryco Psycho]

Lunati has some killer hyd street roller profiles so I would discuss cams with them . I am not familiar with most of the hyd roller cams they have available . Springs retainers & 10 * locks should be added to match the cam . Some clean up in the prts usually will not hurt unless you cut into the wrong areas !
 For what you want to do the Magnum heads should work fine , they are a decent head for a factory casting
Intakes are tough , the Magnum uses a verticle bolt , the LA used a 45* angle so most intakes do not fit the magnum heads , I would look for an RPM dual plane with dual bolt pattern or see what else is available .

[Chryco Psycho]

Summit has a few intakes listed
http://www.summitracing.com/int/parts/pfs-55025/overview/make/dodge
http://www.summitracing.com/int/parts/edl-7577/overview/make/dodge

[joe1978c]

Thanks Chryco. I was looking into an air-gap style intake.  So ur sayin u think the factory magnum heads should work fine w/just having them cleaned up (ported and polished), upgraded springs to match a bigger cam, better locks retainers?  I just didn't know if it would be better to sell those factory magnum  heads complete and go w aftermarkets.  They are brand new and I'm sure I could get atleast a few 100 for them from someone who needs them for a truck rebuild for ex.  Thanks again for your input!!!
-Joe-

[Chryco Psycho]

Just giving you options , you can use aftermarket heads such as Airwolf or RHS but not with the Magnum block if they shaft rocker system

[joe1978c]

Just giving you options , you can use aftermarket heads such as Airwolf or RHS but not with the Magnum block if they shaft rocker system

Thx again Chryco. I hear you bro and appreciate ALL AND ANY HELP AND INPUT/OPINIONS/OPTIONS U KNOW ABOUT!!!!  I have never messed w/a magnum motor b4 so its new territory for me.  Just seemed to be such a great deal to pass on u know? My plan is to make this motor just decent/respectable/reliable, allowing me to focus on restoring the car how I want, THEN going through and building a terror of a motor w/the 340 currently in the car.  What is your opinion of Hughes Performance?  Or Bouchillon Performance? They both seem to have a very good reputation from what I've read. (I ask b/c I used to see people talk about INDY w/reverence and these days I seem to read nothing but negative things, ranging from problems w/products to rude/unhelpful/terrible customer service.  I ALSO realize anyone can post anything, and opinions are like a-holes, w everyone having their own. LOL.)  My thoughts now are leaning towards taking this NOS 300h.p. Mopar Performance Magnum 360, pulling the heads, sending them to someone (Hughes or Bouchillon I'm thinking but am OPEN TO OTHER SUGGESTIONS!), and having them ported/polished/deburred/smoothed, convert from the smaller valves (think 1.88 or 1.92 intake side to 2.02 and on the exhaust I honestly forget but know its pretty simple just like the old LA J heads when they went to a smaller valve (1972?)), having different springs for a higher lift cam installed,  better (assume titanium) retainers, 10* locks, etc.  From your previous advice I'm assuming this should improve the factory magnum heads enough. I am going to check w Lunati as you suggested and also w/Hughes performance for some of their cams (as I hear they make some great profiles for the magnum roller motors) So, a few questions:

1. IYO, do you think just improving the factory magnum heads would be a better (basically more cost efficient and sensible) option than getting aftermarket heads? Since I'm not building a long term motor, only looking for mid 400hp minimum to high 400's if possible (of course more is better..lol)

2. If u were to have someone do the work I mentioned to the factory magnum heads, who would you trust to do it?

3. I saw the links to air-gap intakes you posted (which I appreciate btw), and wondered if u thought/had experience w/any real differences b/t the Edelbrock and Professional Products one? (really b/c Edl. one 2x the price), and would you run that over a Mopar M1 single plane that I always see on the magnum crate motors? I know u mentioned about the magnum intakes being a little trickier, but have found now that you can ALMOST find just about all the intakes u can get for the LA motors for the magnums, though I don't know if performance is the same, in case that's what you were referring to. (I realize u mentioned b4 you'd look for dual rpm and c what's out there, just curious IYO about these and if you've seen any outcomes)?

4. Almost forgot. Would you have heads shaved or trying to run a thinner head gasket to bump up the compression a bit? (think these crate magnums are like 9:1)?

Thanks in advance and again for all of your advice/suggestions/known options/etc. that you have informed me about thus far. Sorry for the bombardment of all the nit picky questions, details and such, but I'm just trying to soak up all the knowledge I can b4 buying or doing ANYTHING. Can't thank you enough brother.

[Chryco Psycho]

The magnum will be fine I am sure , Why not throw a better cam into it , change the intake & run it. You may be happy with the power as is & it will get you through until you cn build the 340, if not you can pull the heads over the winter .
 I am not sure how much gain is available in working the heads , , the magnums do work well stock often larger valves do not make a huge gain with swirl port heads so cutting for larger valves in brand new heads may not be worth the expense , you could deck the heads for a bit more compression but you would have the have either the intake side of the head cut to match or narrow the intake , I would cut the head so any intake will fit & then your intake is not junk if you decided to sell it later on  , I would also check what pistons were used the compression may be higher than you think .
 1] I am not sure what aftermarket heads are available for the Magnum & if there is significant gain , often Eddy heads are a sideways move , lighter being alum but you lose more heat to alum & the real performance gains are often minimal at best .
 2] No clue , I did all my own heads & had some of my own ideas which proved to work well , I hear good things about Dwayne Porter
 3] The Eddy RPM works well , I have no info on the Pro Products one but I assume it is similar although looks can be deceiving ! I love the M1 intakes as well but it is a different intake , the RPM works better low to mid range being a tall dual plane the M1 works better mid to upper range so I would choose based on matching the power band of the cam , torque converter stall etc .
 4] using an alum head I would use Cometic MLS gasket only , with Iron heads a thin steel shim is a good option , I believe the magnum while using a ball stud system like the GM does not have adjustability like the GM so any changes to deck thickness or gasket thickness could cause the adjustability of the hyd roller lifter to go out of range or too close to one end of the adjustment so new pushrods may be needed .
 My experience with Indy has been decent , decent products & service but the customer service has been bad , Hughes is about the same Decent stuff but the customer service sucks & if you can buy similar or better stuff elsewhere why deal with jerks !!  Long story but Hughes has some unique cams but offers no warranty so if the cam fails you are on your own , Engle used to Grand all of Hughes cams so I went to the source & bought direct from Engle , they do or did offer warranty & were great to deal with , Lunati also has some very unique Mopar designed cams & is great to deal with.
 

[joe1978c]

The magnum will be fine I am sure , Why not throw a better cam into it , change the intake & run it. You may be happy with the power as is & it will get you through until you cn build the 340, if not you can pull the heads over the winter .
 I am not sure how much gain is available in working the heads , , the magnums do work well stock often larger valves do not make a huge gain with swirl port heads so cutting for larger valves in brand new heads may not be worth the expense , you could deck the heads for a bit more compression but you would have the have either the intake side of the head cut to match or narrow the intake , I would cut the head so any intake will fit & then your intake is not junk if you decided to sell it later on  , I would also check what pistons were used the compression may be higher than you think .
 1] I am not sure what aftermarket heads are available for the Magnum & if there is significant gain , often Eddy heads are a sideways move , lighter being alum but you lose more heat to alum & the real performance gains are often minimal at best .
 2] No clue , I did all my own heads & had some of my own ideas which proved to work well , I hear good things about Dwayne Porter
 3] The Eddy RPM works well , I have no info on the Pro Products one but I assume it is similar although looks can be deceiving ! I love the M1 intakes as well but it is a different intake , the RPM works better low to mid range being a tall dual plane the M1 works better mid to upper range so I would choose based on matching the power band of the cam , torque converter stall etc .
 4] using an alum head I would use Cometic MLS gasket only , with Iron heads a thin steel shim is a good option , I believe the magnum while using a ball stud system like the GM does not have adjustability like the GM so any changes to deck thickness or gasket thickness could cause the adjustability of the hyd roller lifter to go out of range or too close to one end of the adjustment so new pushrods may be needed .
 My experience with Indy has been decent , decent products & service but the customer service has been bad , Hughes is about the same Decent stuff but the customer service sucks & if you can buy similar or better stuff elsewhere why deal with jerks !!  Long story but Hughes has some unique cams but offers no warranty so if the cam fails you are on your own , Engle used to Grand all of Hughes cams so I went to the source & bought direct from Engle , they do or did offer warranty & were great to deal with , Lunati also has some very unique Mopar designed cams & is great to deal with.

Thx again Chryco. I'm glad you told me all of that, especially [4] and about Indy and Hughes.  I definitely agree w/you about dealing w/jerks.  I probably will just change the cam, intake, (and valve springs at a minimum b/c the stock ones in there are only good to barely over .500 lift). I think I will do some more research about possibly a thinner head gasket, etc since reading your response [4].  I'm almost positive the compression is 9:1 now.  I will also take your advice about looking at Engle and Lunati as options. Thx for the tip.  What's your thoughts about Comp Cams?  It seems I've been seeing a lot of people talk about them offering a lot of cam and valvetrain options lately.  Thx again Chryco!!

[joe1978c]

The magnum will be fine I am sure , Why not throw a better cam into it , change the intake & run it. You may be happy with the power as is & it will get you through until you cn build the 340, if not you can pull the heads over the winter .
 I am not sure how much gain is available in working the heads , , the magnums do work well stock often larger valves do not make a huge gain with swirl port heads so cutting for larger valves in brand new heads may not be worth the expense , you could deck the heads for a bit more compression but you would have the have either the intake side of the head cut to match or narrow the intake , I would cut the head so any intake will fit & then your intake is not junk if you decided to sell it later on  , I would also check what pistons were used the compression may be higher than you think .
 1] I am not sure what aftermarket heads are available for the Magnum & if there is significant gain , often Eddy heads are a sideways move , lighter being alum but you lose more heat to alum & the real performance gains are often minimal at best .
 2] No clue , I did all my own heads & had some of my own ideas which proved to work well , I hear good things about Dwayne Porter
 3] The Eddy RPM works well , I have no info on the Pro Products one but I assume it is similar although looks can be deceiving ! I love the M1 intakes as well but it is a different intake , the RPM works better low to mid range being a tall dual plane the M1 works better mid to upper range so I would choose based on matching the power band of the cam , torque converter stall etc .
 4] using an alum head I would use Cometic MLS gasket only , with Iron heads a thin steel shim is a good option , I believe the magnum while using a ball stud system like the GM does not have adjustability like the GM so any changes to deck thickness or gasket thickness could cause the adjustability of the hyd roller lifter to go out of range or too close to one end of the adjustment so new pushrods may be needed .
 My experience with Indy has been decent , decent products & service but the customer service has been bad , Hughes is about the same Decent stuff but the customer service sucks & if you can buy similar or better stuff elsewhere why deal with jerks !!  Long story but Hughes has some unique cams but offers no warranty so if the cam fails you are on your own , Engle used to Grand all of Hughes cams so I went to the source & bought direct from Engle , they do or did offer warranty & were great to deal with , Lunati also has some very unique Mopar designed cams & is great to deal with.

Oh yeah.  You will probably know.  I see yes and no answers to this but will LA headers work with a Magnum head?  I know the bolt pattern is the same but also know some of the ports are slightly different.  Didn't know about this one, but it seems difficult for me to find long tube headers that will fit an E-body that are Magnum specific.  I mostly just find shorty truck headers (like the ones that came w/my motor) that I prefer NOT to use, which makes sense since this motor only came factory in trucks/suvs.

[Chryco Psycho]

Talk to TTI , I thought they basically used the same port & bolt config .
 Comp is not quite the last company I would use but close they have advertised themselves to the front but the products are not the best for Mopar , others companies are ahead of them in designs for Mopar 

[asm74]

I put these on my 95 5.2L magnum in my 73 challenger (auto trans, PS). 

http://www.summitracing.com/int/parts/dou-d453-r/overview/make/dodge

They fit, look and perform great... although I could swear I got them much cheaper.

[joe1978c]

I put these on my 95 5.2L magnum in my 73 challenger (auto trans, PS). 

http://www.summitracing.com/int/parts/dou-d453-r/overview/make/dodge

They fit, look and perform great... although I could swear I got them much cheaper.

Thanks ASM74 and Chryco.  All info is much appreciated