1991 TBI and HT 383

[hoser1869]

Anyone know if the stock TBI in a 1991 350 Suburban will power a GM HT383 crate engine? if not, any suggestions for a more HP replacement for the tired 190hp that still uses the stock TBI?

[sntrym95]

Maybe? Depends on the RPM range of the cam. I couldn't find it with a quick search.

You would need at least a new fuel pump, regulator, and chip to get it even close to working. Check with Brian at tbichips.com to see if he has something that will work with that motor.

[Tom]

If TBI can support a mild 454 it will easily support a mild 383.

[Kudzupatch]

It can be tuned to work but if you just stick it in and bolt up the TBI, it's not going to work well. The computer is tuned for the old engine and your 383 is going to be a drastic change, so it will probably run, but not right.

You are going to have to tune the computer to work with the engine. No experience with TBIchips and I think the web site is a good source of info, but search the internet and read about the experiences people have had with his mail order tuning. LOTS and LOTS of unhappy people. Common story is they have had him makes 4-6 chips and the car is still not running properly. Lots of unhappy clients.

Again, no personal experience but I have read so many of these stories I wouldn't use him. When I do my engine swap I am going to by an Ostrich chip emulator and learn to do it myself Gearhead EFI forums is a good source of into on tuning.

I never see it mentioned but Holley makes a direct replacement TBI unit that flows 650 cfm. Stock unit is something like 450 CFM which would really limit high RPM performance.

[b454rat]

I had a 406 that was TBI with 10:1 comp. and comp came extreme energy 268, way more motor than that 383, all on 110% stock ecm and fuel stuff. Ran friggin awesome, put 10k I think before I sold it.