i cant seem to find anything about this!

[JohnnyBarnett1981]

hello all i have an '89 chevrolet heavy half 4x4 and the old tbi 350 started rattling the other day and i asked a couple of mechanics about swapping for a '96 to '99 vortec 350 not just the heads but the whole engine and i want to keep my tbi set up and they have all told me its a direct swap as i was sure of since a 350 is a 350 on the outside but i was wondering if the knock sensor was the same i also know ill have to get an intake for the heads that will accept the tbi...what will be the pros and cons of swapping to the later L31 engine instead of going back with an older style tbi engine?? i was told that the vortec 350 will be a power house with the tbi set updue to not being choked down with the later style computer

 

[Tempted]

Vortec 350 will be hindered by the TBI system. Nothing wrong with the swap, though. It is certainly an upgrade and the power difference will be huge. Would be cheapest to use a carb manifold with a TBI adapter. The TBI Vortec manifold is high.

 

[JohnnyBarnett1981]

what makes the tbi a henderence for the vortec? is it the 500 cfm throttle body ? ive also been seeing something about getting the chip reprogrammed for this...what kindof programming would i need to do?

 

[454SSguy]

The 350 TBI doesn't flow very well, if you can find a BBC TBI (link of 1 for sale at bottom) then it would help for sure. I'd go with a single plane low rise intake (torker II, wiend Stealth ,ect) and a carb-TBI adapter. If you want to tune the truck yourself, call BOB at dynamicefi.com and get his EBL kit(~$450), hands down best way to go, get way more mileage out of it (lean cruise), better performance and he will walk you through the tuning (it also self tunes alot of tables). His customer service is like none I've ever seen, he's the man. If you don't want to tune yourself you can get a chip burned from TBIchips.com (~$350) I've heard good things about him. The drawback to this is, you get 1 tune. If you ever change anything or decide you want something different you need a new chip. Or you could avoid all the tuning stuff and go carb, cold starts in the winter and not as good of mileage, but simple.

TBI for sale, on the cheap - http://www.454ss.com/cgi-bin/forum/YaBB.pl?num=1325004423

 

[beast94]

The 350 TBI doesn't flow very well, if you can find a BBC TBI (link of 1 for sale at bottom) then it would help for sure. I'd go with a single plane low rise intake (torker II, wiend Stealth ,ect) and a carb-TBI adapter. If you want to tune the truck yourself, call BOB at dynamicefi.com and get his EBL kit(~$450), hands down best way to go, get way more mileage out of it (lean cruise), better performance and he will walk you through the tuning (it also self tunes alot of tables). His customer service is like none I've ever seen, he's the man. If you don't want to tune yourself you can get a chip burned from TBIchips.com (~$350) I've heard good things about him. The drawback to this is, you get 1 tune. If you ever change anything or decide you want something different you need a new chip. Or you could avoid all the tuning stuff and go carb, cold starts in the winter and not as good of mileage, but simple

TBI for sale, on the cheap - http://www.454ss.com/cgi-bin/forum/YaBB.pl?num=1325004423

I use the EBL on my 2 trucks. I have mostly stock truck that is getting 19 MPG. And a truck that is heavily modified with vortec heads and Im getting 22 MPG with it. Those are combined city and highway averages too. The EBL is easy to install and even easier to tune. And as stated before, Bob is the man! He will help you with anything

 

[copernicusd]

is the bbc tbi just bolt right up?
just need the tune after wards?
see them on ebay for 250, but they make it sound like they have to do something to them to put on a 350

 

[454SSguy]

No, they bolt right up. As mentioned before some of the sensors are different from different years but I'm sure the guys on here can help you with that. Just fyi, then one I posted up the guy was askin $50 but it has no injectors. You can get them in salvage yards for about the same price I think.

 

[Tempted]

And you don't have to re-tune. You would if you change the TBI but just swapping over won't require a new tune.

 

[JohnnyBarnett1981]

what comes with this $450 kit ??

 

[MOBS]

If you're using a carb-to-tbi plate on a vortec-to-carb intake....you need to make sure you get a plate made for the 454tbi, the 350tbi plate will have smaller ports that won't let the 454tbi throttle plates open. The stock 350tbi with no spacers or addons benchtests 485cfm on average.....which is actually a higher number than the tbi heads will flow. When you switch to using vortec heads, the next major bottleneck is ofcourse the tbi then....I wouldn't try to get a very high CR vortec(aka fast burn)engine, as the higher compression and matching cam setup will warrant a new tune to fine tune your setup to the new specs of the engine. The tbi 350's are very low CR engines....they also made 2 different tbi 350's, do you happen to know which one ya got?