Having a premade wiring harness from the '87 Chevy made installing everything much easier for him. Dad left great wiring diagrams and even some "to-do" lists, but he didn't have a chance to finish. But the harness is old. I have already had to repair three wires where they broke or the connectors disintegrated. Someone hooked the distributor wire to the overdrive's governor, which caused the engine to quit when it went over 25MPH. That caused a lot of backfiring while I tried to figure that out. It also probably explains why the injector's electrical connectors are slightly melted. (not sure if dad accidentally did that or one of his friends who tried to get it going before he died.) And if I go with a carburetor and HEI, I will have to make a new wiring harness and make provisions for the fuel pump, which I believe is currently controlled by the ECM. (plus replace the fuel pump with a lower PSI or install a regulator) So either way, there is going to be work to be done. An aftermarket TBI system has all of that bundled. But it is expensive.
Thanks for the advice
Your Dad wasn't wrong to put the TBI onto the Chevy. Sounds like he knew the system-it isn't really that complicated-and Chevys with TBIs were a dime a dozen in any wrecking yard. That was back when you could still routinely walk into a wrecking yard without paying admission and signing a waiver.. but anyway..
I've done it the old way with jets, metering valves, needles and springs. I've made the Edelbrock sitting on the 500 Cadillac in this bus sing the beautiful song of its people while the big V8 pulled this bus up any grade I tried on half throttle. Not at all saying that carb isn't a viable option. But...
Now there's the modern way. Just dial it in on the tablet that comes with the EFI system. No advance weights, no busted vacuum cans, frozen distributor advance plates, ruptured mechanical fuel pump diaphragms filling the crankcase with gas.
I've done it the old way and enjoyed my old carbureted cars. However, nowadays you can tune it with a laptop, and I'll take building a wiring harness and plumbing in high pressure fuel lines all day long over the old way. Only gotta do that wiring job once.
My free advice, that's worth every penny.. ensure that TBI system is grounded-sensors, ECU, everything-to one single bolt that's a short distance from the battery negative terminal. Then run it. It'll last forever.
The old TBI system also has the advantage of relative simplicity in that it's got no VATS to delete, only the one O2 sensor to worry about (and it doesn't even need pre-heat wired into it) and if you'd like more CFM, find the TBI off a 454.
Good times!
