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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Big Katz on March 01, 2013, 01:27:35 am

Title: TBI question
Post by: Big Katz on March 01, 2013, 01:27:35 am

So I have a question for you TBI savvy people. I have a 87 blazer with a 350 TBI system. I also have a 402 BB sitting in the corner of the shop. Can I put a 454 TBI intake, camshaft and  distributor, my 350 TBI and sensors on the big block and have It perform fairly well? I am not not looking for insane power. I am just looking for the low end torque of a big block, but hate to loose the creature comforts of the fuel injection in the winter time. This vehicle tows my boat (4000 lbs) in the summer and is my plow truck in the winter. After owning big blocks and turbo'ed diesels most of my life, stock small blocks just don't do it for me. I was just wondering if it would work seeing how there wasn't a large difference in displacement and that I wasn't looking to run high RPM's.

Title: Re: TBI question
Post by: Fairlane514 on March 01, 2013, 07:35:53 am

How about a torque cam swap for the small block and a lower rear end gear. If you have a 700R4, you will still have overdrive.............of course its hard to tow in overdrive.

Title: Re: TBI question
Post by: Big Katz on March 01, 2013, 12:23:43 pm

I am going to drop the gearing down to 4:11 gears next month. With a TBI system can you install any style cam and have the fuel system still work properly?

Title: Re: TBI question
Post by: DanInMichigan on March 01, 2013, 12:46:04 pm

I'm not a tbi expert but I think the answer is no.  If the vacuum signal changes too much I think that would confuse the computer.

If you call summit they can probably help you find one certified for tbi.

Dan

Title: Re: TBI question
Post by: bd on March 01, 2013, 02:14:14 pm

Just an opinion:
I think you would be seriously disappointed.  The SB TBI won't flow enough air or deliver enough fuel for a BB application.  It's barely adequate for a SB.  You would be better off sourcing a complete BB system.

Title: Re: TBI question
Post by: Captkaos on March 04, 2013, 11:39:54 pm

You can make it work, but it won't be making huge amounts of power..  The 454 used a 50mm Throttle body vs 46mm on a SBC, 80 & 90 lb injector vs 55 & 65, and a different chip..  Any you have to get a computer friendly cam..

Title: Re: TBI question
Post by: DnStClr on March 09, 2013, 12:27:48 pm

Big Katz, for what you're trying to do you might enjoy reading the info from the tbi chips site- altho he writes mainly for improving the camaro performance, there's some good stuff for truck performance too.
http://www.tbichips.com/305mods.htm