where did the 70s take the horses

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.