5.7l injectors in a 7.4l TBI

[eyeroc87]

balanced and blueprinted 5.7l, cam, 2.02 fulie heads.MSD and headers, my plan is to run a 7.4l TBI unit, it flows 740cfm. with 5.7l injectors, anyone done this? opinions, advice.?.

 

[L31MaxExpress]

balanced and blueprinted 5.7l, cam, 2.02 fulie heads.MSD and headers, my plan is to run a 7.4l TBI unit, it flows 740cfm. with 5.7l injectors, anyone done this? opinions, advice.?.

They will be too small. Stick with the 7.4 injectors and tune the ECM.

 

[someotherguy]

balanced and blueprinted 5.7l, cam, 2.02 fulie heads.MSD and headers, my plan is to run a 7.4l TBI unit, it flows 740cfm. with 5.7l injectors, anyone done this? opinions, advice.?.

They will be too small. Stick with the 7.4 injectors and tune the ECM.

Not sure if I agree...but especially if they are 1994-1995 7.4 injectors they won't be anywhere near enough at regular small block TBI pump pressure, so application definitely matters here

Richard

 

[Casey1104]

I put 454 injectors in my 1989 chevy k1500 heavy half pick up truck they fit but they were tight.

 

[L31MaxExpress]

Not sure if I agree...but especially if they are 1994-1995 7.4 injectors they won't be anywhere near enough at regular small block TBI pump pressure, so application definitely matters here

Richard

That also depends on what small block you are talking about.

The factory 4.3s and 350s with speed governors on the TBI used big truck 366/427 throttle bodies.

My first upgrade on these trucks is always the fuel pump and adquate fuel delivery. It is the only way you can make any power.

The 300 hp Mercruiser 350 TBI engines used the high pressure version of the 46 lb/hr 4.3 injectors at 30 psi. The 400 hp 502 used a high pressure version of the 61 lb/hr 350 injector at 30 psi.

You must be registered for see images attach

 

[someotherguy]

I mentioned it in reference to OP is running a 5.7 and did not mention changing the pump so he'll be at 13psi, or less. Not sure why you'e bringing up other combinations.

Richard

 

[Elroy]

i did a built TBI 350 years ago, used a bored TB and bigger injectors from Turbo city in Aneheim, they seem to have all that stuff

 

[L31MaxExpress]

I mentioned it in reference to OP is running a 5.7 and did not mention changing the pump so he'll be at 13psi, or less. Not sure why you'e bringing up other combinations.

Richard

Because the OP made no mention of what his 5.7 is in. The picture and information I posted above is a factory GM combination on a 5.7. It had a governed TBI unti and 366/427 injectors which ran at 30 psi.

 

[someotherguy]

Because the OP made no mention of what his 5.7 is in. The picture and information I posted above is a factory GM combination on a 5.7. It had a governed TBI unti and 366/427 injectors which ran at 30 psi.

Sure is a lot of hypothetical going on in that response considering it's for a post on GMT400.com but knock yourself out.

Also curious why the handle change?

Richard

 

[L31MaxExpress]

Sure is a lot of hypothetical going on in that response considering it's for a post on GMT400.com but knock yourself out.

Also curious why the handle change?

Richard

It is a factory GMT400 combination, provided it had the speed governor option from the factory. Used on the 91-95 TBI trucks and full size. Mostly fleet stuff though.