Crate engine issues

Ok, so about 2 years ago I replaced the engine in my 91 RS with a 350 crate from Summit. Exept we replaced the Holley 650 with the stock TBI and a new manifold, we also replaced the stock distributor with a higher performance distributor

http://store.summitracing.com/partdetail.asp?part=NAL%2D12496968&autoview=sku

Me and my dad are just now getting around to putting it on the dyno and having the computer re-worked. We brought it in to a local guy we know to have all the work done, and after a few hours we got a call back saying that the engine would perform better with the old carb. and distributor. Me and my father were a little confused about this, we figured the TBI and new distributor would give us more power and efficiency if the computer was calibrated to suit the engine's needs. I would just like more opinions before we consider ripping the engine apart again. Thanks :sunglasse:

The TBI unit may be restircting air flow and that is why they suggested going back to a carb. You'd need to match a TBI unit's flow ability to what size carb was recommended.

Do you have any idea of what the CFM rating is for the 305 TBI?

Do you have any idea of what the CFM rating is for the 305 TBI?
LOW, much lower than one of Summit's crate 350's would need/want.

Are there any modifications I can make other than getting a new TBI?

Are there any modifications I can make other than getting a new TBI?
You could try larger injectors and you'll need a PROM programmed for a 350, just for a base to tune from.

If I remember correctly, there was a Chevy truck with a 454 which used TBI's, that would bolt up to a 350 with minor modifcations. Am I right? If so which truck was it from?

If I remember correctly, there was a Chevy truck with a 454 which used TBI's, that would bolt up to a 350 with minor modifcations. Am I right? If so which truck was it from?
You could try one from a Vortec 350, that should bolt right up and need minimal tuning.

the 454 tbi was on the 80's suburbans, they have larger injectors and a 2" bore, you'll need an intake manifold with 2" bores to match it tho.

You could try one from a Vortec 350, that should bolt right up and need minimal tuning.

:1:

That or get a tunnel ram and run a couple 2 barrel carbs.

isn't the tbi from the 350's the same as the one on 305's?

isn't the tbi from the 350's the same as the one on 305's?
No. It is a larger unit with larger injectora. Also, it will be a newer generation of TBI, more efficent, more powerful.