Author Topic: upgrading to a big block  (Read 4845 times)

Offline mach3107

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Re: upgrading to a big block
« Reply #15 on: October 31, 2007 - 07:57:02 PM »
do I need to change anything with the steering components? I have the power steering pump still mounted on the 440.




Offline 73Chally

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Re: upgrading to a big block
« Reply #16 on: October 31, 2007 - 08:04:02 PM »
I have not added subframe connectors, and I'm not sure if I will at any time.  The only track time my car will see will be the occasional fun-n-grudge at the local 1/8 mile, but If you plan on racing your car I would definitely add them.  As for the leaf springs, they will give a very firm ride, which again will be a big plus if you race.  I kind of went overboard with my suspension, but I was tired of the bouncy ride from the stock suspension, and wanted to get the best performance ride with the best possible stock setup.  I have the Hemi T Bars, X-HD leaf springs, front and rear sway bars, and all new bushings.  For a total of about $1,000 in parts, I feel I have as good a suspension as I possibly could, without getting too much into the XV and Just Suspensions stuff.  Everything except my rear swaybar is Mopar Performance.

As for the steering pump, if I remember correctly, the same pump was used that was on the 340.  The only new part needed for that was the BB pulley.
« Last Edit: October 31, 2007 - 08:07:04 PM by 73Chally »

Offline 72hemi

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Re: upgrading to a big block
« Reply #17 on: October 31, 2007 - 08:22:11 PM »
I think the pump brackets are different as well on the big block.
1972 Dodge Challenger 340 6 Pack 4-speed
1996 Dodge Viper GTS Coupe

Offline 73Chally

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Re: upgrading to a big block
« Reply #18 on: October 31, 2007 - 08:26:01 PM »
I think the pump brackets are different as well on the big block.
That's correct.  I forgot about that.

Offline Chlngrcrzy

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Re: upgrading to a big block
« Reply #19 on: October 31, 2007 - 08:55:56 PM »
I am looking at swapping out my motor also. What about motor mounts? What will you need to go from a 318 to a 440?
Will most headers fit or will i have to get a certain kind.

Offline gomopar440

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Re: upgrading to a big block
« Reply #20 on: October 31, 2007 - 09:16:21 PM »
You'll need the first set of brackets on the top of the page here ---> http://www.440source.com/enginesupportbrackets.htm

and

one of the first three mounts listed here to go with them (the second one is the reinforced one) ---> http://www.440source.com/enginemounts.htm

You can get them many other places, these are just the first place I found them when I looked.

Offline 73Chally

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Re: upgrading to a big block
« Reply #21 on: October 31, 2007 - 09:19:48 PM »
A set of big block motor mounts will work for the 383, 440, and I believe the 400, also.  If you're lucky enough to have a Hemi, then you will need a different set (along with a Hemi K-Frame).  As far as headers are concerned,  the best fit will probably be with a set of TTIs, but you're looking at $1,000+ for a good set of theirs.  I bought a set of Hooker Headers for around $200, and with a little "modification" (A ball peen hammer to crimp in a couple spots), got them to fit without much problem.  The biggest fitment issues are with the starter and power steering box.  If you have a mini starter and/or manual steering box, then you will be ahead of the game.

Offline gomopar440

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Re: upgrading to a big block
« Reply #22 on: October 31, 2007 - 09:21:25 PM »
I think the pump brackets are different as well on the big block.


He said it was still mounted on the 440 so he may be good. I'm not positive though since it came out of a truck he may still need the pass car mounts if they are different. Since I had the site still up from my last post, I looked over at 440source and found these ---> http://www.440source.com/powersteering.htm .  I belive Bouchillon also has the PS mounts if needed.

Offline mach3107

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Re: upgrading to a big block
« Reply #23 on: October 31, 2007 - 09:28:55 PM »
I know I need the 440 motor mounts but I also need the adapters?

Offline 73Chally

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Re: upgrading to a big block
« Reply #24 on: October 31, 2007 - 09:37:01 PM »
Yes.  These are a 2 piece mount, where 1 piece bolts to each side of the block and the supports bolt to the cradle of the K frame.  You drop the mount onto the support and then bolt them together.  Here's a used set on Ebay:

http://cgi.ebay.com/ebaymotors/BIG-BLOCK-MOPAR-ENGINE-MOUNTS_W0QQitemZ110187061163QQihZ001QQcategoryZ140688QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
















Offline 72hemi

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Re: upgrading to a big block
« Reply #25 on: October 31, 2007 - 10:15:44 PM »
Also being a truck motor you will have to check what side of the engine the lower radiator hose comes out of. I have seen 2 truck motors where the lower radiator hose comes out in the same side that the small blocks do, where most big blocks have it on the other side. You will also want a 26 inch radiator, which hopefully your car had factory or you will have to widen the radiator support to support a 26 inch.
1972 Dodge Challenger 340 6 Pack 4-speed
1996 Dodge Viper GTS Coupe

Offline mach3107

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Re: upgrading to a big block
« Reply #26 on: October 31, 2007 - 10:20:03 PM »
It didn't come with a radiator. I'll have to get a 26 and see witch support I have

thanks for all the info so for. I'm sure I'll have more questions

Offline HP2

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Re: upgrading to a big block
« Reply #27 on: November 01, 2007 - 02:52:19 PM »
What kind of suspension and brake upgrades are recommended when going to a big block? 

In general, disc brakes, bigger t-bars, better leaf springs.

how much difference does th HD leaf springs add/ what the advantage?

These provide better resistance to spring wrap up, which is going to plant your power better.  Your stock 318 car came with 4 leafs per spring. The XHD set wil step that up to 6.5 without becoming extremely rough riding.

The standard BB torsion bars I believe are 0.92" diameter, whereas the Hemi and HD torsion bars are 0.96" diameter. 


Hemi cars came with .92 bars. Most others had .88. I think 318s were down to .82. I don't have my service manual in front of me, but they were down there in size. IMO, .96 bars are a good recommendation for a small block car and street handling. For a big block, you want a 1.0" bar. Combine with with a 1" front sway bar and the XHD leaf spring and you've got a great basic package for all around street driving, comfort, and performance. Match these with Edelbrock, Pro, or MP shocks for a budget or use Konis or QA1 adjustables for an awesome set up.

Subframe connectors are, IMO necessary for any old car. After 30+ years of unibody flexing, the additional rigidity of these provide improve ride performance, road feel, and over all pleasure of driving. They shouldn't be considered a racing only improvement and with the torque of a big block, you will notice the difference. Try this, jack up one corner of your car and then open the door. Sub frame connectors will fix the problem you'll see when you do this.

Offline jeryst

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Re: upgrading to a big block
« Reply #28 on: November 07, 2007 - 12:01:27 PM »
I put a 383 in a 318 Cuda years ago. All I needed was the motor mounts, and it drove and handled fine. Didn't have any problems with overheating or anything. Do that first, and then impliment the other fine suggestions as your budget permits.

Offline MyMopar

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Re: upgrading to a big block
« Reply #29 on: November 07, 2007 - 02:25:46 PM »
I swapped out a 318 in my 73 Challenger for a 440.  Was a quick job. 
Needed teh following parts:
1. 440
2. Big block 727 transmission
3. Driveshaft - no one mentioned this but you will need it modified for length
4. T-bars, went with the .96 size
5. Had my spring pack rebuilt with superior parts and extra leafs
6. Exhaust new system and Hedman headers (I think)
7. Radiator - passenger in/drivers out
8. Power steering brackets
9. Upgraded ignition system
10. Driveshaft loop

This winter I'll add rear disc brakes, aluminum radiator and a new 727 w/GV OD unit.  If any money left, aluminum heads.
1969 (OO===]|[===OO)
1973 (OO/=====\OO) <---SOLD
1997 (O|||||O) <---SOLD

Smoke tires, not drugs!