On a basically stock 85 305 TPI, with usual free/low buck mods( airfoil, K&n's,gutted air box, forced cold air, 160* t-stadt, base timing bumped, 92 octane, bosch-4's, tpis wires, maf screens & fins,etc) how much h.p. increase can I realistically expect by porting stock plenum, siamizeed runners ,and porting stock intake (base). Since plenum is easiest to get at, will that alone make any real diff, or should I do base and siamizee runners too?.Has anyone whos gone through the effort felt it was/ was not worth gain/ time spent? Any responses would be appreciated Thanks & Happy New Year.

 

One mans port job flows worse than stock, and another's flows better than lingenfelter all depends on that