rearend

my thruck started out as a base 4.3l 5 speed reg cab work truck 2003. I am in the prosess of swaping my 6.0l now a 6.6l into it . I need to know what kind of rearend it has on it there is no tag for some reason. Bassicly I need to know what this axle will hold up hp wise. and what kind it is . My truck is bagged so there are brackets welded onto the housing so a swap isn't really a good idea HELP!!

Most 1/2 ton trucks have a 8-5/8" ring and pinion but they call it a 8-1/2" 10 bolt unit.

Thanks . do you know how much they cand handel. or what manufactures make strong enough axles ,gears that will fit into that housing? just a guess hopefully I will be making somewhere in the ballpark of 500 to the wheels. are the easy to beef up?

The parts are readily available most anywhere. The rear end will hold 600+ hp easily. I don't know anyone with real problems using the stock 10 bolt with a good posi/limited slip differential added to it. There are plenty of guys running turbos pushing over 500 hp without issue. You can add a billet cover to beef it up a little if it makes you feel better. Go for GM gears if you can afford them. Otherwise, Richmond will do the trick. Gears and an install kit should be just at $300. A posi/LSD will run anywhere from $300-$700 depending on what you buy.

What kind of rearend do you call a good one? I heard some bad stuff about the Eatons....

I think the Eaton is a posi,or lsd unit only

Yea thats what I meant, what's a good LSD?

Auburn or Eaton either one will get the job done. As far as the how tough the 8.5 10 bolt is, I wouldn't worry about it too much. Just slap a posi & some gears in it & go. When it breaks then think about upgrading, but you probably won't have to worry about that for awhile, unless you plan on doing some 4500rpm launches with a transbrake & slicks.

I'm on my second truck with an Auburn posi/LSD. These things are tough. I bought this one off of Ebay for $80 I think. It came out of a low mileage Caprice.

$80 that's a pretty good deal! I think I paid a hundred & something for mine on ebay & I thought that was a good price.