EFI upgrade?

[Gordy_]

Here's a little background on my truck before I flood y'all with questions about it:
She a 1989 gmc sierra slx k1500. She has the 4.3L v6 backed by a 5spd manual transmission. I bought her out of a feild for 500 bucks a few months ago and have been dailying her for a month or 2 in town and highway. One of the main things I had to do was a new fuel pump and rebuild the EFI. I rebuilt it with a kit from NAPA and made sure to clean everything really good. It runs good. But pretty darn rich. I don't really care to troubleshoot the EFI in it, I just want to eventually replace it.

The major question I have is can I slap a 4 barrel manifold on this and run a holley sniper EFI? My train of thought is the truck is manual and doesn't need a signal from the ECM to shift, and the timing is off a distributor. In my mind this swap is doable, but I figured I should ask the experts.

Keep in mind this won't be for a while. I have to drive this thing across the country to move and won't be able to do anything to it for a while. However when I make it out to Kentucky I plan to pull this thing into the shop, yank the engine and tranny to rebuild both of them, put the truck on the lift and replace all the seals and fluids in the drive train, and undercoat the truck. I was wanting to do this swap after rebuilding the engine if that's possible.

Thanks guys!

 

[Komet]

You can do that. But you should probably do it to a 350.

 

[Drunkcanuk]

Sure you could do that, but for a 4.3, that would be crazy in my opinion!
If it's running rich, figure out why.
Is the 02 sensor working properly?
What makes you think it's running rich?
Is the exhaust burning your eyes?

The reason I say that's crazy is more of a financial one than anything else. The cost of a Sniper and intake would definitely be more than swapping in a 5.3LS and you would have a modernish V8 and $$$ left over.

 

[Sean Buick 76]

Yes if you like the 4.3 just get it running right. I wouldn’t rebuild a NV-3500 trans unless it had issues.

 

[1998_K1500_Sub]

If it's running rich, figure out why.
Is the 02 sensor working properly?
What makes you think it's running rich?
Is the exhaust burning your eyes?

^^^ this, and "Is the catalytic converter functional?" It'll smell like a '66 BelAir if it's missing the cat.

 

[Gordy_]

Yes if you like the 4.3 just get it running right. I wouldn’t rebuild a NV-3500 trans unless it had issues.

The input shaft bearing is shot and rattles alot

 

[Gordy_]

^^^ this, and "Is the catalytic converter functional?" It'll smell like a '66 BelAir if it's missing the cat.

Who knows. I'm not replacing it if I don't have to.

 

[Gordy_]

Sure you could do that, but for a 4.3, that would be crazy in my opinion!
If it's running rich, figure out why.
Is the 02 sensor working properly?
What makes you think it's running rich?
Is the exhaust burning your eyes?

The reason I say that's crazy is more of a financial one than anything else. The cost of a Sniper and intake would definitely be more than swapping in a 5.3LS and you would have a modernish V8 and $$$ left over.

I can smell it's running rich, plus the heavy soot in the tail pipe. I don't really care about price and I like the V6. I just think it would be fun to do and would be interesting for sure.

 

[Sean Buick 76]

Who knows. I'm not replacing it if I don't have to.

Cut out the cat unless you need it for inspection

 

[1998_K1500_Sub]

Who knows. I'm not replacing it if I don't have to.

If you think it's running rich b/c it smells rich, this (the cat) might be the reason.