As far as the modular motors go, when i refer to one of them, i simply ask if its a 2, 3 or 4 valve motor.
I perfer DOHC. 4 cams, 2 over each head. My 3.0L DOHCv6 designed in the early 80's makes 220hp and revs to 7500...:) ALSO, there are valve train differences including buckets and shims and...