454 Throttle body or 46-47mm modified 350 TB?

[arrg]

I take it launching in 4WD means instant carnage?

???

 

[1990Z71Swede]

???

Hmm 3 question marks... I'm going to interpret that as both PlayingWithTBI and the pirate are 2WD/C1500 boys and that launching a K1500 in 4WD is absolutely fine

 

[1990Z71Swede]

Just going to update with a bit of information I stumbled upon regarding the 454 TBI´s
Old news for some I´m sure, but here goes.

There is an Early and a Late Model Throttle body, The Early 454 model is very much like the 350 throttle body, but with bigger Blades and larger IAC passage. The later 454 has a different foot print and much revised IAC passages.

Even the 350 Throttle bodies come in at least three revisions. All three have changes done the IAC passages. Some versions of the 350 TBI´s seem to have more meat left for the gasket to seal against when enlarged to 46mm than others.

Picture from Thirdgen.org

Who is atually using a GM 454 TBI unit on a SBC? - Third Generation F-Body Message Boards

TBI - Who is atually using a GM 454 TBI unit on a SBC? - Just curious. I have one of these laying around and while surely its possibly to fab a TV cable mount, I want to know who has actually done it. Is it more feasible to have my small bore TBI bored out to near the same size?

www.thirdgen.org

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Early 88-90 350 Throttle Body

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One of the Later Model 350 TB´s

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Yet another but slightly different Early TB, Not a lot of meat around the bores here, on the other hand it does look like the bores are larger than stock, not listed as such on ebay though

You must be registered for see images attach

 

[L31MaxExpress]

Just going to update with a bit of information I stumbled upon regarding the 454 TBI´s
Old news for some I´m sure, but here goes.

There is an Early and a Late Model Throttle body, The Early 454 model is very much like the 350 throttle body, but with bigger Blades and larger IAC passage. The later 454 has a different foot print and much revised IAC passages.

Even the 350 Throttle bodies come in at least three revisions. All three have changes done the IAC passages. Some versions of the 350 TBI´s seem to have more meat left for the gasket to seal against when enlarged to 46mm than others.

Picture from Thirdgen.org

Who is atually using a GM 454 TBI unit on a SBC? - Third Generation F-Body Message Boards

TBI - Who is atually using a GM 454 TBI unit on a SBC? - Just curious. I have one of these laying around and while surely its possibly to fab a TV cable mount, I want to know who has actually done it. Is it more feasible to have my small bore TBI bored out to near the same size?

www.thirdgen.org

You must be registered for see images attach

Early 88-90 350 Throttle Body

You must be registered for see images attach

One of the Later Model 350 TB´s

You must be registered for see images attach

Yet another but slightly different Early TB, Not a lot of meat around the bores here, on the other hand it does look like the bores are larger than stock, not listed as such on ebay though

You must be registered for see images attach

The last TBI pictured looks like a bored out SBC TBI.

 

[1990Z71Swede]

The last TBI pictured looks like a bored out SBC TBI.

Yes I think so too. The picture is from Ebay and the seller has several TB´s listed, both standard and 46mm. I think he/they just mixed up the pictures. Still the IAC channel is different than the other two 350 TB´s. Obviously GM has done a fair bit of tweaking here.

The Reason I´ve been paying attention to this is that otherwise informative page on the Interwebs where it is advised against using a 454 TB on a 350 because of alleged idle control issues. I think if there is any truth to that It might be related to the use of the late style 454 TB. At least I hope so because I´ve decided to go with the early 454 TB

 

[Schurkey]

Make sure you use the correct gasket to go with the throttle body.

 

[L31MaxExpress]

Yes I think so too. The picture is from Ebay and the seller has several TB´s listed, both standard and 46mm. I think he/they just mixed up the pictures. Still the IAC channel is different than the other two 350 TB´s. Obviously GM has done a fair bit of tweaking here.

The Reason I´ve been paying attention to this is that otherwise informative page on the Interwebs where it is advised against using a 454 TB on a 350 because of alleged idle control issues. I think if there is any truth to that It might be related to the use of the late style 454 TB. At least I hope so because I´ve decided to go with the early 454 TB

I have used both styles on a small block without idle issues. Some 4.3Ls even had the large footprint later style 454 TBI without issues.

 

[PlayingWithTBI]

I think if there is any truth to that It might be related to the use of the late style 454 TB. At least I hope so because I´ve decided to go with the early 454 TB

With which injectors at what pressure?

I have used both styles on a small block without idle issues.

Same question, with which injectors at what pressure?

I'm genuinely curious because I may go down that road too. As you may recall, I'm getting 90 MAP with WOT at higher revs up to 5700, on my 46 mm TB (on a 3704 intake manifold bored to 48mm). I have no problem achieving 12.5 AFR with my 61 LB/Hr (5.7L) injectors at 20 PSI.

 

[1990Z71Swede]

With which injectors at what pressure?

IDK. But I get what you are talking about,

With which injectors at what pressure?


Same question, with which injectors at what pressure?

I'm genuinely curious because I may go down that road too. As you may recall, I'm getting 90 MAP with WOT at higher revs up to 5700, on my 46 mm TB (on a 3704 intake manifold bored to 48mm). I have no problem achieving 12.5 AFR with my 61 LB/Hr (5.7L) injectors at 20 PSI.

IDK about the injectors. Are you running the stock TBI Throttle body to Air cleaner spacer? I think that could be somewhat restrictive.

I'm going to fab something up so I could use a flat base air cleaner on the throttle body, that means using a 1-2" taller filter element than stock. Not sure if such a filter exist in stock (13"?)diameter?

Edit: I guess it does
WIX 46220
Is that one perhaps for the 454 trucks?

 

[PlayingWithTBI]

Are you running the stock TBI Throttle body to Air cleaner spacer?

Yes, I am. Look up "TBI salad bowl spacer", they say it helps. YMMV

Edit: here's one.

JEGS 50080: TBI Air Flow Enhancer Fits: 1985-97 GM 5.0 & 5.7L TBI equipped trucks - JEGS

Get the Best Performance with JEGS TBI Air Flow Enhancer Fits: 1985-97 GM 5.0 & 5.7L TBI equipped trucks 50080 parts at JEGS. Shop Now at the Guaranteed Lowest Price!

www.jegs.com

I'm going to fab something up so I could use a flat base air cleaner on the throttle body, that means using a 1-2" taller filter element than stock. Not sure if such a filter exist in stock (13"?)diameter?

I'm using the 14" Edelbrock 43661 it has the top element for better breathing.

Edelbrock 43661 Edelbrock Pro-Flo High-Flow Series Air Cleaners | Summit Racing

Free Shipping - Edelbrock Pro-Flo High-Flow Series Air Cleaners with qualifying orders of $109. Shop Air Cleaners at Summit Racing.

www.summitracing.com

With this Moroso bottom plate for better clearance over the Ignition Coil wires.

Moroso 97090 Moroso Air Cleaner Bases | Summit Racing

Free Shipping - Moroso Air Cleaner Bases with qualifying orders of $109. Shop Air Cleaner Bottoms at Summit Racing.

www.summitracing.com