I just got a written-off 1993 GMC half ton with a 162k 350 in it via no reserve silent auction for $100. STEAL imho... im gonna salvage some parts and make a profit from the body alone. I was wonder if anyone knew what the engine code was for this or whatever (im new) like L98 or whatever. And was also wonderin where i could get an adapter kit so i can stick the 350 into my 700R4, which is currently burdened by a 305. was also wonderin if it would be safe to slap the 305 heads onto this 350? im carbing/rebuilding this motor, for daily driver/mustang eater. also, anyone have a good recomendation for a cam thats daily driver friendly, yet still has some punch? please i dont feel like getting flamed on something stupid, so only positive opinions, thanks.

 

IIRC the engine code is L05.

It's a TBI motor. The heads suck. They are "swirl-port", with this giant lump in the intake that the factory calls a "ramp". It's designed to promote low-end (<2000 RPM) torque and gas mileage, at the specific expense of power output.

As far as whether your 305 heads would be "better", that would depend on what 305 heads they are. Some would be better, some would be about the same, some would be worse. Casting numbers would be the thing that identifies which you have.

No "adapter kit" is required. There's virtually ZERO difference, externally, between a 305 and a 350.

 

89 305 iroc stock heads... i have no clue what the casting #'s are, i dont have the car here.

 

The '89 IROC could have either the LO3 TBI 305 or the LB9 TPI 305. If the former, you're better off with the 350 heads. If the latter, those are a decent choice on a 350, but having 1.94" intake valves installed would make them even better.