I was just given an 88 C1500 with a blown 305 engine. Found a 89 350 engine with intake but no TBI. Best I can tell from other posts here is that all I need to do is install TBI injectors from 350 engine in my 305 TBI and should be no problems. Right? Having a problem with mid throttle lag and some spark knock. No Lag without load on engine, Put it on the road it has a dead spot and at about 40% to 75% throttle has serious lag. Timing is at 10 degrees and wire was removed and replaced before trying again on road. Have gone up to 13 degrees and down as far as 8 degrees. (Pretty fire show there) No change. Almost sounds like rev limiter cutting back the engine. It does not have one, I don't think.
Also another question, I have the work truck front end. You know the one with the single headlight, the ugly one. Is it possible to put the front end (grill and head lights) from a 96 and up silverado without replacing the radiator support?

Thanks for any advice;
Josh

 

The ECM chip is different for the 350. I did this same swap in a 1995 and had all kinds of problems till I changed the ECM chip. I think you are alright swapping just the injectors in the Throttle Body. I think I swapped my entire throttle body out trying to diagnose the problem before I realized it was ECM. Since you need to buy a chip anyway you could order an aftermarket performance chip (like a superchip) for the same year you have but just with a 350.