Mopardude said
I just scored another A-body 8 3/4 rear end so now both my A-bodies has one and I can get rid of this B-body 8 3/4 I have. For some crazy reason the guy I bought this new rear end from cut the perches off of it. He gave me some new ones to put on it. He told me they need to be welded on at a 5 degree angle. Does this sound about right? I want to check his numbers before I have someone weld them back on. Also the center hole in these perches are a little over 5/8 of an inch, am I wrong or isn't the hole for A-body perches supposed to be like 1/2 inch?
Also this rear end I got came with a 742 case. So now I have one of each kind of case. I know the 741 is considered the weakest, and thats in the B-body housing anyways, so I am just going to sell that as complete. How does the 489 and 742 stack up against each other? From what I understand is the 742 doesn't have a crush sleeve but the 489 has a bigger pinion.
Also from what I understand from other threads I seen posted lately is that my 74 Dart Sport should have a 7 1/4 that has 3" tubes so the shock plates and u-bolts and brake hardware I should be able to reuse from it. I would like to go caltracs but don't want to spend that kind of money right now. Could I get away with reusing the 7 1/4 springs too?
Hi Tim,
I may not be ableto answer all of your questions, but I'll try.
Personally I like the 742 casting myself. IMO they are equally as strong. Of course if you use a 489 casting, be sure to eliminate the crush sleeve with a solid spacer. I am not sure on the later 7 1/4 tubes being 3", maybe someone will chime in on that. If not, you'll need the shock plates etc, for the 8.75.
As for your pinion angle, most guys will set the rear end up in the car with the perches loose and unwelded, so you can adjust your angle. Once you are content with your angle, you can either mark the perches, or tack weld them in place then remove the rear and weld the perches on.
As for the hole in the perches, I know the MP ones have a larger hole. I am sure you could machine up a spacer to go in there to take up the slack if you really wanted to.