I just bought a 2 owner 85 318 Ramcharger myself & it is a dog (weighs exactly 4300 lbs without me in it). For the effort it really needs a 360 or a 5.9. Yes your mods will help but you might not get as much benefit as you would like, maybe maybe not but yeah I'd go ahead & do some parts swapping, that's the name of the game. The lack of cubes vs weight and low compression is hurting us on this. I'd suggest a Hughes cam and extensive dist mods. EDIT & headers/free flow (mandrel) ex/muffs