it was 85 up 318s got a comp bump to the 9.0 to 1 with a taller piston comp height and the closed swirl port chamber #302 heads. from the few police 85-up 4v318 engines I owned, I found they had the 9.0 to 1 piston comp height but the open chamber 360 heads drops it down almost a full point of comp. what is really different is the cams the 4v 318 use to maximize the 360 head flow.
so if you take a 2v 318 with the #302 heads 9.0 to 1 comp ratio and drop on a set of 360 heads/intake it does 2 things. 1 it drop comp ratio, 2 it still has a whimpy 2v cam with less than .400" lift
Stock cam in a 2bbl or 4bbl 318 was the same during the flat tappet era. The stock cam in a 360 was barely over .400" lift anyway. Even when they went roller the cam specs didn't really change much between the roller 2bbl's and the flat tappet 4bbl 318's. A few more degrees intake duration was about it. Lift and exhaust duration were the same but your point about the 340 cam is well taken. For the money it's probably the best option out there. basically any 318 needs a different cam from stock to wake it up.
