where did the 70s take the horses

YY1 said

My research indicates that except for 67 (first year for LA 31 8, all the cams were the same until the 87-ish roller motors.

318 2 barrel 67 Hydraulic 390/390 244/244
318 2 barrel through 88 Hydraulic 373/400 240/248

Going from 390/400 lift to almost any of the 441-ish "mild" cams that don't even require new springs or valve guide work has GOT to be a substantial improvement.

Click to expand...

Not really. If you go back starting in 67-74 and track the 273/318 hydraulic cam it changes slightly.

I did a study many years ago (can't find it now without researching all service manuals again). The duration changed in the 240, 248 ranges. sometimes split duration, sometimes even. And I think lift was .399" or like .410" without going back and doing it all over again. You have to really pay attention to detail to catch the differences. It slipped by me for a while and I had to go back and recheck when I first did my study.