will J heads work on a 318? And many many more questions.

what size valve are in your j heads? the 1.88 would work better but with stock pistons they are too far in the hole to get the compression up to be able to use the cam you have if you change the pistons to some zero deck you would be able to maybe use that cam and the j heads if you milled them you should be able to sell them for as much as you can get the later 318 heads for or you can find the magnum heads cheap for your stock bottom end and pistons the eddy cam and closed chamber heads it will run grate lots of torque probably 260 hp and 350 ft lbs my guess