Crate engine issues

[drumcat]

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/partde...8&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 :

[Morley]

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.

[drumcat]

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

[Morley]

Originally Posted by drumcat

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.

[drumcat]

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

[Morley]

Originally Posted by drumcat

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.

[drumcat]

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?

[Morley]

Originally Posted by drumcat

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.

[Genopsyde]

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.

[hotrod_chevyz]

Originally Posted by Morley

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

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

[Genopsyde]

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

[Morley]

Originally Posted by Genopsyde

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.