I just dropped my 1984 dodge 318 off at the engine shop, Ive done a lot of reading on this motor already I'm going with the comp cam 268h cam kit. I'm keeping the stock heads I have a edelbrock aluminum dual plane intake, and a edelbrock 600cfm four barrel carb. My main question is can I get 10:1 compression out of this motor with stock heads? The motor is getting all new pistons and the heads are getting freshened up as well so I figured why not bump the compression up a little. Another question is what is the stock compression of a 84 dodge d100 318? The cam kit instructions say for best performance of the cam kit for compression to be 9:1 to 9:5:1. I'm not trying to make 400hp I'm just trying to make a nice reliable fun driving truck I'm after torque more than horsepower.

 

THe engine shop should be able to get you to what you want 9.5.1 or 10.0.1... Should be your choice...

 

Thanks for the response Bob, I guess what I'm curious about is there much to gain 9:1 to 10:1? I know the stock heads can only flow so much so before I make the decision on compression I'm wondering whats the most compression I can get out of the stock heads.

 

If your just looking to stick with the Iron heads that you have. My suggestion would be to, have the heads ported and gasket matched and a good 3 angle valve job. Set the compression at 9.5.1 and a 270* cam. should run good from Idle to 5500 to 6000... Just my 2 cents...

 

Ok sounds good that was what I was after, so hopefully the comp cam kit I bought should be perfect for what I'm trying to do.

 

I have ran the Comp Cam Extreme 268H in a 9.5.1 360 Small block create engine with smog 360 heads. I used a 2800 stall converter in a truck with a little to tall of a rearend gear 2.73 ratio. And a 33" tall tire. With the Cali blend fuels we have to run and as heavy as the truck was. It tended to ping if you stepped into the throttle too hard... I never was too happy with that set up. Sold that to a guy that drove it till he wrecked it ! (about 70,000 miles later)
But your 318 should be a little more forgiving, Just cant leave them pistons too far down in the hole....
Who's doing the work up in the Truckee area? Hope it's a Mopar guy?

 

HP gains will be minimal, if you plan any towing/hauling 10:1 is a bad idea. I would go 9:1, our 318 truck engine with a XE254H cam was 8.5:1 compression based on what our trusted builder suggested. Engine has great power and torque no pinging with trailer on.

 

The motor is getting built by a shop that I have used before he is doing 4 mopar motors now including mine, my truck is a standard cab short box d100 and has a 4speed 833 transmission with a 2:73 or a 3:23 gear I cant remember ill have to recheck the codes. I'm going to be lowering the truck so my tire size will be short and I will be running 93 octane in this truck so I shouldn't have any pinging issues.