newbe looking to my $ worth!

[cudaaah]

My restored 70 Cuda 4 spd has a 73 stock, (strong), 440, yet I believe came out of a motor home ( low HP).  I have added MSD electronic ignition, edlebrock performer manifold w/ 850 CFM edlebrock carb. Once tuned and timed I noticed I nice difference.

Problem: I've purchased a 6pac intake and carb set-up for the car, but have since been told I need to spend roughly another 7-10K ( heads, cam, timing chain, starter, headers ) to properly rebuild engine to notice any change.  I have a 71 resto project in the wings that I'm intending to put some $ into it and don't want to spend that kind of $ on my 70.  I'm not trying to build a race car, but would like to get better performance out of my 70.  I'm somewhat novice w/ engine mechanics, but am extremely motivated and quick learner. 

I'm OK w/ spending $4-5 K additional on my 70, but  don't want, if possible, to spend much more since the 71 is what I'll be puting $ into. 

I'd appreciate any honest feedback so I will know what my options may or may not be.  Can I either set up my 70 w/ the 6pac, or existing intake and carb and  improve the HP?

Thanks
Cudaaah

[Chryco Psycho]

you will feel the 6 pack , but with a well designed cam & some head porting it will really turn on even with the low compression
 using either 516 or 915 heads will bump the compression a point as well

[cudaaah]

Who makes a 516 or 915 head, I'm not sure what that is?  I'm starting to learn about chamber size, open or closed, as well as intake and exhaust valve sizes and why they're important...  I think what I'd like to find out is a good combination of heads and cam, to justify putting on the 6pac vs 4 bbl.

Thanks
Cudaaah   

[Chryco Psycho]

the 516 are 64-67 383 heads , the 915 are the 67 440 heads
both are production castings

[gomangoRT/SE]

You can get by without spending a whole lot less than $7 to $10,000.   Whomever said that is silly.     Pistons and rings $600 or less.   Cam and Kit $450,   bearings say around $200,  of course a new oil pump high volume $60 easy, then spend $500 or less on good machine work and having the rotating assembly balanced.   The heads Cryco mentioned are fairly easily found.   Closed chamber bumps the compression.   I see these heads for under $250 all the time, probably some on moparts.com or ebay even now.    Usually you can find a party who has become disinterested who has already had valve or porting work done to them for $600 finished.    Your out for under $3000 since you have the sixpack set up and intake manifold.     

[Chryco Psycho]

  you can rebuild the short block for way less than $7k

[cudaaah]

Ok. I called mopar performance hotline and was given a suggestion on heads, and cam to match my 6pac set up .  I purchased alluminum heads (summit racing model#p4876311) that are designed after the 906 heads that came w/ the 440 sixpack, but improved.  It has 2.14 intake and 1.81 exhaust...again this is replacing my stock 902 heads out of my 73 440.  I went w/ a purple cam w/ 292 duration. A Cloyes roller timing chain.  Obviously new valve springs and manley valves. 

I've since been told by one of my many expert friends??? that due to the fact my block is a low compression engine, that this may hurt my performance.   It's tough being new!

I did pull my heads and I have flat head pistons that show .30 on them...I know the rings are good, and the car ran well B4. 

Any further opinions would be appreciated since the heads will take 2 weeks to come in.  I would appreciate input on my choices.


Thanks
Cudaaah

[Chryco Psycho]

measure how far the pistons are down the hole at TDC

[EVIL72]

 You could of just asked Chryco Psyco he's our own personal Mopar performance hotline! 
 So the cam you ordered is the MP 509 lift. Are your new Aluminum Mopar performance heads closed chamber?, I couldn't find much info about them except for the 2.14-1.81 valves.

 
 

[cudaaah]

I do'nt have the proper measuring tool to check the height if the piston @TDC, but it looks to be about an 1/8th of an inch from the top of the cylinder wall.  As far as the head, I toow as looking for the complete specs on the head, but couldn't find...I guess I was relying on Mopar to properly direct me.  I'll call them back this morning.

Thanks
Cudaaah

I am learning!

[Chryco Psycho]

well with the piston .125 down the hole you have approx 7.8:1 compression + with alum heads the effecticve compression drops 1 more point to 6.8 :1 you should have no problems running 60 octane fuel

[cudaaah]

Is there anything you'd suggest w/ this engine w/out building the bottom end?  Or should I just leave it alone?

Cudaaah

[Chryco Psycho]

Sorry I mage a mistake , the heads is listed with a smaller but unspecified size combustion chamber so your effective compression should be in the mid 7:1 range even with the alum heads , Using a low overlap short duration cam like an Engle K 56 will build a lot of compression so you will not feel the lack of compression as much, other than that you need to put in a set of pistons

[gomangoRT/SE]

I think you are still missing a piece of this puzzle.   How good are the heads going to do you with your very low compression ratio.    I mean if Chryco is right mid 7 to 1 compression ratio is low.......  I mean low.    You need to be running a minimum of 9.5 to 1 with this kind of head.     I dunno it seems you have put the cart before the horse.    Or maybe you have the cart but not the horse.    I would think your low end torque would be weak.     Perhaps I am wrong, but thats the way I see it.

[cudaaah]

Ya know I think your right...I called today and cancelled the heads, I'm sending back the cam and putting my car back together as it was.  I don't want a major job right now w/ my 70, due to the fact I've got one with my 71.

As I've mentioned I'm on a learning curve, and I've just gonr to grammer, jr., and high school plus a little college!   It's amazing the # of experts out there and the wide variety of opinions, my head's been spinning.  All I wanted was a liitle more HP.  It may not be the quickest car out there, but I do enjoy it.

I think I'll take the advice I was given here, seeing there is no alterior motive, and put this project on hold until I finish my 71 cuda and gain a little more experience.    Assuming I'll have any cash left over!

Thanks for the feedback,
Cudaaah