The problem 318 suffer from besides smaller displacement is intake lift, especially after emission regs hit. Ford and GM on their bread and butter engines did the same thing, intake lift short by 0.050". Ford 302, Chev 305 and Mopar 318. When Ford and Chev brought out their HO 302 and 305, they put 350 cams in.
I had a 1982 Blazer 2WD with 305 4 barrel and 700R4. 15MPG, low vaccum and it shift cycled in and out of OD. I bought an RV cam with 214/224 duration at .050 lift and .420 lift. Intake lift was about .070 more than stock. Al.ost totally eliminated the shift cycling and mileage improved to 19MPG. Everyone says the 305 Chev is a toilet engine also.
