Early Corvette rear vs. later model

[J68Bird]

OK, since you guys got me into this, I need you to help me out on this one. When I started this project, a 68 Firebird Conv. all I wanted was a nice car. Then I started reading all the posts on Pro-Touring and decided that I needed alot more stuff. It started with the big Corvette brakes up front. Then came a mini tub. Then I figured that since I have to cut the frame rails (in questionable condition anyway) I might as well replace them with 2X3 pre-bent rails. Since I'm moving the rails, why not go ahead and put the full Corvette IRS in there. While mentioning to my neighbor that I'll be putting in a Corvette rear he say's that he's got one I can have. Problem is, it's from a '68. So my question is, should I use this rear or sell it and get a later model unit? What are the pro's & con's? I have to add that I'm doing all the work myself and having a blast, but each change in plans ends up costing more and pushing back the completion date.

J. Clear

[TitoJones]

Sell it. Look for the C4 IRS rears for the project. I am doing a 96 Dana 44 in a 67 right now. The Wayne Due weld in IRS kit is a dream. This would not be as straight forward without it.
Tyler

[Lowend]

The 63-81 Corvette rearends are not bad pieces, but they do have flaws. There is a major geometry error built into the strut rod placement, it can be corrected for a couple hunderd bucks worth of parts, but its there. The rearends are not the strongest pieces, but if you blueprint the limited slip/ring&pinion they will take a ton of power.
The halfshafts are a weakpoint, make sure you use u-joints without zerk fittings on them.
The main bushing on the trailing arm needs to be replaced with a big spherical bearing to really work properly.

The C4 rearend is a better piece but they have trouble with blowing out hub/bearing assy's. Plan on doing all of the bushings in the trailing arms, a wise man would use spherical bearings there as well.