help with 318 upgrade

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68bb

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Hello All,

Car is a 39k mile 70 dart with 318, 4 speed,3.55 8 3/4 suregrip, and is used for cruise nights and weekend driving. I would like to do some low dollar upgrades on the 318. This is a "for now" motor and later on we'll build a 360 or stroker with a block I have. Here is a list of what parts I have accumulated over the years and I would be thankful for some advice on which way to go. We have a set of stock magnum heads that have been fully machined and set up for a little over .500 lift, professional products intake, used hooker headers, set of 340 hipo exhaust manifolds, comp cams hi energy cam 218/218 454 454(not extreme energy), edelblock 600 cfm carb.I was thinking not to pull the motor apart, just do the top end and new timing chain. What do you think, use any of these parts or go with something else?

thanks
 
Run a compression test on all cyls to make sure you are not wasting your time, otherwise the rest of your plan sounds pretty good, I don't think you will be unhappy with those upgrades.

When you do pull the heads off the 318 get the deck height of each cyl so you can calculate CR and tune the build a bit - don't be surprised if you find flat-top dished pistons in there as factory CR was in the 8.6:1 range - the closed chamber of the magnum heads will bump your CR up and help use all of a 600cfm carb

I'm sure others will have better advice for you
 
yes, will do the compression test first. What about the headers versus the manifolds? Is there a better cam or is that good enough?

thanks
 
68bb said:
yes, will do the compression test first. What about the headers versus the manifolds? Is there a better cam or is that good enough?

thanks
Click to expand...

For max HP go with headers, manifolds will be easier fit-wise

That cam (20-212-2) should be fine for the 318

You will have to use AMC style lifters and hollow pushrods to run the magnum heads as oiling through the pushrods is required vs. the stock LA head oiling setup
 
I vote for the Mag heads and the other top end gear you have. Should be right around 315 h.p with that cam. The 1.6 rocker will give you extra lift and it will be a .484 cam.
 
Sinceit is a just for now set up, it looks good. Go for it.
 
Thanks for the input guys. Just upgraded to the 4 speed and 3.55 and just that made it feel a whole lot better
 
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