Originally Posted by 99Rampower
I have a 1999 dodge ram with a 318 in it. I hae a complete 360 minus the head that i am planning on rebuilding and installing in my truck. All i am going to do is bore it .030 over and put in a mild cam and a good exhaust. My main question is will my 318 heads fit on the 360 block? I know that the 318 has more compression(8.5:1 compared to 7.2:1 if thats right) which is another bonus if it will work another is will the computer work or will i have to swap that as well or will a computer chip compensate for the larger displacement. Any info would be great.
The 318 heads fit the 360 yes. The compression in the 318 and 360 is 9.1:1 roughly, depends on tolerances. But the compression you should work with is the compression based on the swept volume which is the distance from the piston crown to the deck when the intake valve closes. This is much more accurate, to find that distance you just have to do a little trig very easy. If you want my honest opinion you would benefit from using comp cams 20-604-9 and setup everything so you can have a DCR of about 8.0-8.5:1. If you use the cast iron heads you will want to use a 180 degree thermostat and probably mid-grade fuel, fuel selection will be iffy you have to but it on a brake dyno and calibrate from there just like the engineers (hello) do. But if you do that you will have some serious power, with the proper head flow and precise crank balancing you could see lower to mid 400, with the correct fuel mapping and calibration. All in the calibration.
Oh the stock DCR for a 318 is around 7.7-7.9:1
I never calculated the DCR for the 360, but it's going to be close to the same because they both ask for octane 87.