Re: 4L80E Q's
Just as an FYI, the 4L80E is only available in Trucks, Vans, and SUV's. That is, unless somebody's swapped it into a f-body or some other chassis. And to make it more difficult, it's only available in 3/4 ton or heavier chassis. It can be found behind everything from 4.3l v6's (in vans) to big blocks (which later went to Allisons as they became available).
It is best to get as late a trans as possible. As George said, avoid the early transmissions (pre'93) like the plague. Personally, I wouldn't touch anything prior to '99, because GM has made a bunch of revisions ove the years, trying to make the trans stouter. Big changes, like lube circuits, and gears that are significantly thicker (like 10% or round abouts) are some of the changes that GM has made.
Depending upon where you live, and how hard you shop, you should be able to get a good running trans for about what you're figuring for a core. Don't limit yourself to just your local salvage yard, shipping a trans can save you a bunch of money. Personally, I like Car-Parts.com. From it, I located and bought an '04 80E for $800 (complete & running including the converter) and a '04 6.0L V8 for $1200 (both from the same truck) shipped to my door for $140. Both are in my Bravada now and run great (had 26,xxx miles on them when the truck was wrecked).
'JustDreamin'
