Gm Crate Engine Question

sledfreak · September 15, 2009

Hey guys new here.. I have a 1990 GMC 2 wheel drive Sierra STn short box truck. I want to replace my current 5.7L 195hp with a new GMC ZZ4 crate engine. The problem is my truck is Throttle body and that motor will require a carb? Can I make this work and run a carb with my current computer and electronics. I was told was all I realy had to do is to put in a manuel fuel pump, but will my guage still work. I would like to put in a motor that has 350-400hp. Any help here would be really appreciated. I am also not really that inclined, but I will get someone else to do the work, I just want to know if it is possible to make this happen.

Thanks...

93_Silverado · September 15, 2009

Hey guys new here.. I have a 1990 GMC 2 wheel drive Sierra STn short box truck. I want to replace my current 5.7L 195hp with a new GMC ZZ4 crate engine. The problem is my truck is Throttle body and that motor will require a carb? Can I make this work and run a carb with my current computer and electronics. I was told was all I realy had to do is to put in a manuel fuel pump, but will my guage still work. I would like to put in a motor that has 350-400hp. Any help here would be really appreciated. I am also not really that inclined, but I will get someone else to do the work, I just want to know if it is possible to make this happen.

Thanks...

I don't see why it wont work but make sure you have a carb with an elec. choke if you live somewhere it's cold or you'll be cranking that thing forever. You should do a build thread with pics!!

WilliamBos · September 15, 2009

Why does it require a carb?? IMHO, TBI is really a glorified carb anyway.

Hey guys new here.. I have a 1990 GMC 2 wheel drive Sierra STn short box truck. I want to replace my current 5.7L 195hp with a new GMC ZZ4 crate engine. The problem is my truck is Throttle body and that motor will require a carb? Can I make this work and run a carb with my current computer and electronics. I was told was all I realy had to do is to put in a manuel fuel pump, but will my guage still work. I would like to put in a motor that has 350-400hp. Any help here would be really appreciated. I am also not really that inclined, but I will get someone else to do the work, I just want to know if it is possible to make this happen.

Thanks...

ZZ327 · September 15, 2009

as far as I know, You could call into GM performance parts to double check. You should be able to bolt your whole intake or just the TBI to your new engine. There isnt much computer controlled on the TBI 350s other than the throttle body

93_Silverado · September 16, 2009

as far as I know, You could call into GM performance parts to double check. You should be able to bolt your whole intake or just the TBI to your new engine. There isnt much computer controlled on the TBI 350s other than the throttle body

I think that the carb would be better, I have heard on alot of other forums that the TBI doesn't perform very well on high performance engines and you would have more ability to tune with a carb.

WilliamBos · September 16, 2009

I think that the carb would be better, I have heard on alot of other forums that the TBI doesn't perform very well on high performance engines and you would have more ability to tune with a carb.

Change your injectors if need be. Why step backwards to a carb??

txab · September 16, 2009

nvm

sledfreak · September 16, 2009

Thanks for the posts guys... I agree, if I could just bolt on the throttle body, then yes that would be great, but I don't believe it would give the right amount of fuel for the 350hp that the ZZ4 will produce. Here is a pic of my truck..

It's pretty much stock and original except for the front grill (wife hit a snowbank and broke the grill), 2" drop and Sir Michaels roll pan.

It's in real good shape and their is no rust on it any where, being from canada and all.

sledfreak · September 16, 2009

nvm

What's nvm?

sledfreak · September 16, 2009

as far as I know, You could call into GM performance parts to double check. You should be able to bolt your whole intake or just the TBI to your new engine. There isnt much computer controlled on the TBI 350s other than the throttle body

I'm a newbie on this. I have tried calling some gm performance in Canada and I got no where. Does anyone know of any GM performance shops that can give me the truth on how this can be done. Thanks alot for the help.

sledfreak · September 16, 2009

This is the motor, I would like to put in it.

http://www.gmperformanceparts.com/EngineSh...2&engCat=sb

66nova · September 17, 2009

I think that the carb would be better, I have heard on alot of other forums that the TBI doesn't perform very well on high performance engines and you would have more ability to tune with a carb.

Change your injectors if need be. Why step backwards to a carb??

As far as I am concerned using a TBI on that motor is a step backwards. There is no way in hell that the stock manifold and even a TBI with upgraded injectors is going to make as much power as that motor is capable of.

That motor is designed for a 4 barrel carb and upgraded intake. For only 350 hp engine the TBI probably won't be you biggest problem, but the intake will. As long as you are not talking about putting a Quadrajunk on there. If you want the best performance then go Holley, Demon, etc (4150 style) if you want dependable daily driver Edelbrock or Carter AFB is hard to beat.

What are you going to do as far as transmission goes? That may be where you run into some problems. You may have to have a custom chip burned. But, you should not have any real problems with an OBD1 system going to a Carb set up.

WilliamBos · September 17, 2009

As far as I am concerned using a TBI on that motor is a step backwards. There is no way in hell that the stock manifold and even a TBI with upgraded injectors is going to make as much power as that motor is capable of.

That motor is designed for a 4 barrel carb and upgraded intake. For only 350 hp engine the TBI probably won't be you biggest problem, but the intake will. As long as you are not talking about putting a Quadrajunk on there. If you want the best performance then go Holley, Demon, etc (4150 style) if you want dependable daily driver Edelbrock or Carter AFB is hard to beat.

What are you going to do as far as transmission goes? That may be where you run into some problems. You may have to have a custom chip burned. But, you should not have any real problems with an OBD1 system going to a Carb set up.

Nothing wrong with a Quadrajet, why do you think Edelbrock builds them?? I would never run a Holley, they are JUNK, but I guess because everyone and their mother runs one, they are the best.

I would go EFI on this one. No carb will ever be able to compete with it. E-testing should something the OP needs to consider before spending the money on this one. That is not going away.

To the OP - Sweet truck. The Sierra ST was a nice looking ride, still is.

93_Silverado · September 17, 2009

I think that the carb would be better, I have heard on alot of other forums that the TBI doesn't perform very well on high performance engines and you would have more ability to tune with a carb.

Change your injectors if need be. Why step backwards to a carb??

As far as I am concerned using a TBI on that motor is a step backwards. There is no way in hell that the stock manifold and even a TBI with upgraded injectors is going to make as much power as that motor is capable of.

That motor is designed for a 4 barrel carb and upgraded intake. For only 350 hp engine the TBI probably won't be you biggest problem, but the intake will. As long as you are not talking about putting a Quadrajunk on there. If you want the best performance then go Holley, Demon, etc (4150 style) if you want dependable daily driver Edelbrock or Carter AFB is hard to beat.

What are you going to do as far as transmission goes? That may be where you run into some problems. You may have to have a custom chip burned. But, you should not have any real problems with an OBD1 system going to a Carb set up.

x2 A Edelbrock Carb is hard to beat for a daily driver I have a 600cfm on my Stroker motor in my Firebird and it starts every time, Just keep up on the maint. and it will last a long time.

sledfreak · September 18, 2009

I think that the carb would be better, I have heard on alot of other forums that the TBI doesn't perform very well on high performance engines and you would have more ability to tune with a carb.

Change your injectors if need be. Why step backwards to a carb??

As far as I am concerned using a TBI on that motor is a step backwards. There is no way in hell that the stock manifold and even a TBI with upgraded injectors is going to make as much power as that motor is capable of.

That motor is designed for a 4 barrel carb and upgraded intake. For only 350 hp engine the TBI probably won't be you biggest problem, but the intake will. As long as you are not talking about putting a Quadrajunk on there. If you want the best performance then go Holley, Demon, etc (4150 style) if you want dependable daily driver Edelbrock or Carter AFB is hard to beat.

What are you going to do as far as transmission goes? That may be where you run into some problems. You may have to have a custom chip burned. But, you should not have any real problems with an OBD1 system going to a Carb set up.

Not sure yet on the tranni... Rightnow, I am running the stock one, but not sure about the tranny? What do you think I should I run for transmissions and gears. It will be just a cruiser, but I may take it on the highway the odd time.

Back to the motor, so if I convert it to a carb, what issues will I be looking at when installing and getting it running. Do I just need to run a mechanical fuel pump on the motor and that's it? Any ideas of what it entails to make this work in my truck. Thanks..