Engine delima - advice sought

[Oilbrnr]

Here's the situation; I've got a '77 K5 that I got from the original owner going on three years ago. Sands Chevrolet here in Phoenix put a GoodWrench long block in it in '97. It has about 30k on it, and is consuming oil at a growing rate via the valve guides.

I have a 2007 Silverado 4.8l LSx that needs the alt/ps alum. bracket and and alt/pump. (came from a major driver side wreck, I'm assuming...) Downside, I'm worried that it would strong enough for the K5. Yeah on paper it is very comparable to the old 5.7, but... Also, I'd need to get all the other parts to get it installed, including figuring out what flywheel/clutch combo will work.

Then again, I could try and pick up a decent 454 in running shape and drop it in.

I'm running the stock 3.73 gears and 33's, and it was/will be my DD during the work week. (trying to save the Duramax!)

So rebuild the 350, do the LS swap (with a small V8) or go 454?