97 vortec to carb swap

[Dk47]

I've asked questions about this and saw some good build threads. I also keep getting questions on why would I ever want to do that. Is there anyone who has done this and driven it for a while and been happy with it?

 

[Erik the Awful]

I believe it's typically done when someone can't diagnose the factory EFI. In rarer cases the owner has made modifications outside the capability of the factory EFI. It doesn't take much to outstrip the capabilities of the TBI, but the Vortec has a lot more overhead for performance.

My TBI couldn't handle my cam, so instead of a carb swap I went with a Holley Sniper. The same engine ran fine in a Vortec truck.

 

[95burban]

There are many carb vortec engines, they make great power. You will find most of them in hot rods and early trucks. I have on in a s10.

As far as removing the efi in your 97 and going carb that might be tricky because of the trans needing the ecm. You would need a standalone trans controller to make it easy. It’s all simple stuff but to make it work still cost $$$, if your not in it for performance I don’t think I would do it

 

[Dk47]

I believe it's typically done when someone can't diagnose the factory EFI. In rarer cases the owner has made modifications outside the capability of the factory EFI. It doesn't take much to outstrip the capabilities of the TBI, but the Vortec has a lot more overhead for performance.

My TBI couldn't handle my cam, so instead of a carb swap I went with a Holley Sniper. The same engine ran fine in a Vortec truck.

How about the mpfi upgrade? I'm rebuilding the engine and beefing up the heads, new cam, and flat top Pistons, so I'm making the horsepower if the mpfi can take it. This ain't a daily driver, more of a project

 

[Erik the Awful]

About five years ago my son nuked the engine in our '99 Suburban, so I built another engine from a 4-bolt TBI block. I put Vortec heads on it, put in a Lunati 20080720 cam, flat top pistons (about 9.7:1 compression), put a bigger exhaust behind the stock manifolds, and did the MPFI conversion on the intake. It ran strong even without a tune, but the engine was ticking. I pulled it back out and found the engine in great shape. A .020" hole in the oil gallery plug behind the timing chain fixed the tick. I ended up selling the Suburban, and installed the engine in my '89 Stepside with headers, a dual plane intake, and a Holley Sniper.

The MPFI conversion is such an upgrade from the cheapskate factory poppet system that I'd consider doing it even if the poppets are working fine. It gives a very smooth idle.