rear center and front tbi adapters which do i need? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Scott26 · 01-30-2012, 09:32 PM

Im wanting to know the difference between front mount rear and center mounts. I Have a stock 1986 4 barrel quadrajet intake, and im looking to buy a carb to tbi adapter but i need to know which of one i need. thank you. And is there a adapter that is ca legal?

Turbo85GMC · 01-30-2012, 10:18 PM

There is an actual GM carb-to-tbi adapter that they used on the 454's with TBI. (afaik they never made a big block TBI intake, they just made the adapter) It has nice smooth transitions, not like the flat plate adapters.
Just my $0.02, ymmv.

Turbo85GMC · 01-30-2012, 10:22 PM

FritzA · 02-04-2012, 02:27 PM

The rear offset is more like the stock tbi manifold. No idea why GM made it like that. The middle ones are for people doing conversions who won't be changing their throttle cable which went to the center in the quadrajets.

BLE 'BURBAN · 02-05-2012, 03:57 PM

Quote:

Originally Posted by Turbo85GMC

These on the 454 were also plumbed into the heater lines to keep the tbi throttle plates from icing up in extreme cold conditions.

01-30-2012, 09:32 PM	#1
Scott26 Registered User Join Date: Nov 2010 Location: Fresno California Posts: 65	rear center and front tbi adapters which do i need? Im wanting to know the difference between front mount rear and center mounts. I Have a stock 1986 4 barrel quadrajet intake, and im looking to buy a carb to tbi adapter but i need to know which of one i need. thank you. And is there a adapter that is ca legal? __________________ 1986 GMC Sierra Classic 4X4 Last edited by Scott26; 01-30-2012 at 10:01 PM.

01-30-2012, 10:18 PM	#2
Turbo85GMC Registered User Join Date: Apr 2005 Location: Medford, MA Posts: 307	Re: rear center and front tbi adapters which do i need? There is an actual GM carb-to-tbi adapter that they used on the 454's with TBI. (afaik they never made a big block TBI intake, they just made the adapter) It has nice smooth transitions, not like the flat plate adapters. Just my $0.02, ymmv. __________________ '85 GMC 1500 "Friends don't let friends drive stock!"

01-30-2012, 10:22 PM	#3
Turbo85GMC Registered User Join Date: Apr 2005 Location: Medford, MA Posts: 307	Re: rear center and front tbi adapters which do i need? __________________ '85 GMC 1500 "Friends don't let friends drive stock!"

02-04-2012, 02:27 PM	#4
FritzA Registered User Join Date: Jul 2009 Location: Denver Burbs, CO Posts: 115	Re: rear center and front tbi adapters which do i need? The rear offset is more like the stock tbi manifold. No idea why GM made it like that. The middle ones are for people doing conversions who won't be changing their throttle cable which went to the center in the quadrajets.



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