1999 K2500 Suburban repower options

[oifla]

Hello all,

Have a much loved 1999 Suburban K2500 with the 7.4L (454) vortec. Original engine needs rebuilt (lower end noises, low oil pressure) but I don't have time to do it right now. Instead, I'd like to swap something in while I take my time working on the big block. Four options as far as I can tell:

a) there's lots of 5.7L Vortecs around to be had with the entire donor vehicle. could swap the engine in but I'm not sure what else needs to be adapted. exhaust? (this is the cheapest option)

b) find an 6.0 LS donor. Not sure what is involved but if I had the donor, I can figure it out.

c) look for a 6.5L diesel? I don't know what's required as far as anything beyong the engine itself

d) bite the bullet and pay for a 554 (this is the most expensive option)

Thoughts? Any other options I'm not thinking about?

Thanks
O.

 

[Erik the Awful]

If your plan is to rebuild the original and reinstall it, I'd go with another 454.

or

Pull the engine, slap bearings, check clearances and reinstall. With experience, a buddy, and a three-day weekend you can get it done.

 

[b454rat]

Can't find a good used 454 in ur area? Too bad wasn't closer, I have one that I'll prolly never use. I have 3 of em. What are your plans for the truck? Towing? Driver? I had a crew can with the 5.7 and just normal driving was a dog. There's a reason the bigger trucks and SUV's got the 454. But it's possible to swap it all over. Ideally would need one from another 3/4 or 1 ton, then the wiring would be 100% match.

 

[oifla]

Can't find a good used 454 in ur area? Too bad wasn't closer, I have one that I'll prolly never use. I have 3 of em. What are your plans for the truck? Towing? Driver? I had a crew can with the 5.7 and just normal driving was a dog. There's a reason the bigger trucks and SUV's got the 454. But it's possible to swap it all over. Ideally would need one from another 3/4 or 1 ton, then the wiring would be 100% match.

Good questions.

We use it as a family mover. I have other tow vehicles so it will likely never tow anything anymore.

You're saying a 3/4 ton or 1 ton because they already come with the 4L80E?

O.

 

[b454rat]

OK makes sense. The 3/4 and 1 tons will come with the 4L80, but the wiring between a 1/2 ton and 3/4 are different. But if you have a complete donor, then can take everything off donor and put it on yours without hacking anything. In theory lol.

 

[Keeper]

I'd drop a used 7.4 in there to hold the spot, use the same accesories, wiring, etc. Plus, the reinstall would be easier too.

 

[1952Chevy]

When I had this issue I was able to find a donor truck with a solid 454 in it. Paid 1000, sold parts and scrapped the rest for 1300 total, and got a good running motor out of it.

 

[oifla]

When I had this issue I was able to find a donor truck with a solid 454 in it. Paid 1000, sold parts and scrapped the rest for 1300 total, and got a good running motor out of it.

That would be fine by me but I can't find one that's even worth considering (I'd be glad to get close to breaking even!).

I'm in Central Indiana, if anybody has anything, let me know!

O.

 

[SUBURBAN5]

More of a question but would the ht383e be an option? It's specifically says for 1/2 tons but I've seen them installed in 1 tons... however the before engine was always a 5.7 vortec.

 

[OutlawDrifter]

+1 for slapping in another 454. Too much trouble to swap it over and then swap back if you go SBC or LS.