yes but compression police say you lose putting 2.02 jhead on 68 318 and thats true but they have never run it
the flow matters more
cam 484/carb/intake etc
then spray erases the comp lost by another 130 hp and gives you loads of low end
cheap easy fun
Yeah you probably end up losing nothing because if the added flow from the better heads and bigger valves. Chrysler made police package 318s with 360 heads on them so compression wasn't all too important to them and those motors would haul the mail.