350 swap?

[Gordy_]

So my truck has the 4.3l efi engine. She's an 89 k1500. Would I be able to bolt in a 350 chevy and sniper efi without dealing with driveshafts needing made? I just want a little more hauling practicality out of the truck.

 

[Moofus02]

The 350 will bolt right to your 4.3l transmission. I believe you will need the v8 mounts but I'm not sure

 

[Drunkcanuk]

As long as you are staying with the same transmission, all good on the driveshaft.
You will need new motor mounts as @Moofus02 mentioned.
Watch "Eric the car guy" videos on YouTube, part of the dads truck playlist, goes through all the hassles of installing a Sniper.

 

[Sean Buick 76]

Yes your truck has a v6 specced 4L60e so my suggestion is to find a TBI 5.7, 60e donor truck and steal the engine, electrical complete with fuse block ECU etc as well as the trans. Swap all of it in place of your current emgine and trans and swap over the electrical to the 5.7 stuff. Easy swap. No need to modify anything in the drivelines just bolt the new emgine and trans pair in.

Note, you can in theory keep your current trans and swap the engine only but then you get into the minor differences between the different year 60e trans and also the v6 versions aren’t setup with the same stuff inside vs the v8 versions.

 

[Gordy_]

I don't have a 4l60e, I have the getrag 290 5spd. I have plans to rebuild the transmission and engine, but I figured if I'm in there and have the money I might as well drop a v8 in. This would be probably a next summer project however. Thanks fo4 the info guys!

 

[fancyTBI]

To do the swap:
350
Injectors for a 350
V8 motor mounts
V8 radiator
350/5-speed computer and PROM (you could always just get the right computer and make a PROM if you wanted)
Clutch and flywheel

You can re-use:
Your harness, might need to extend a wire or two
Your accessory brackets and accessories. Though I’d search for the later year brackets, they are aluminum

There are some other things I am forgetting. When you start the swap you should see which part numbers for the V6 and the V8 cross reference each other. That will save you money on buying new parts.

I did this swap in 2018 with my dad. I learned a ton. We spent a lot of time cleaning things up and replacing parts. We probably didn’t have to do as much but it looked and operated like it was factory.

 

[Drunkcanuk]

To do the swap:
350
Injectors for a 350
V8 motor mounts
V8 radiator
350/5-speed computer and PROM (you could always just get the right computer and make a PROM if you wanted)
Clutch and flywheel

You can re-use:
Your harness, might need to extend a wire or two
Your accessory brackets and accessories. Though I’d search for the later year brackets, they are aluminum

There are some other things I am forgetting. When you start the swap you should see which part numbers for the V6 and the V8 cross reference each other. That will save you money on buying new parts.

I did this swap in 2018 with my dad. I learned a ton. We spent a lot of time cleaning things up and replacing parts. We probably didn’t have to do as much but it looked and operated like it was factory.

He's planning on using a Holley Sniper I believe.

 

[fancyTBI]

He's planning on using a Holley Sniper I believe.

You are right.

OP, I can’t help with much of the wiring on that (what’s different, what’s the same) but the hard parts I listed should still get you there.

 

[Schurkey]

Don't forget the pilot bearing/bushing in the back of the crankshaft.

"Good luck" with the Sniper.

 

[Moofus02]

You are right.

OP, I can’t help with much of the wiring on that (what’s different, what’s the same) but the hard parts I listed should still get you there.

You could also use elb flash with a tbi setup but it doesn't quite self tune like the sniper