7.5 vs 8.8 June 05, 2006, 06:55:52 PM Ok after reading the 8.8 issues or non-issues for people, I was wondering what all the advantages are of the 8.8. Yeah it's bigger and has a locker??? But how about if I want to take my "one wheel wonder" and turn it into a posi? With my absolute lack of knowledge of cars (please ask bike questions) I wonder if a posi out of a 7.5 ranger or bronco II will work in my '88 5.0 T-Bird... I think both units are 28 spline. I plan on autocrossing this puppy... and be able to drive it home!:confused: Quote Selected
7.5 vs 8.8 Reply #1 – June 05, 2006, 07:18:02 PM The guts from those rear ends should work fine in yours.The main reason most people change to 8.8" is because of thier ability to handle more power. My 7.5" broke behind a stock 302 with 140 horses. If weight is a big concern, though, you might want to stick with the 7.5". Changing to an 8.8 will pack about 80 lbs onto your car. Quote Selected
7.5 vs 8.8 Reply #2 – June 05, 2006, 07:18:18 PM why not put a TC rear in and be done? Quote Selected
7.5 vs 8.8 Reply #3 – June 05, 2006, 07:36:32 PM When it comes to cars I'm mechanically reclined. The following thread is a little intimidating: http://www.foxtbirdcougarforums.com/showthread.php?t=3664Also, mentioned two up, 80lbs in weight??? No thanks. I add enough weight when I sit in it:D Quote Selected
7.5 vs 8.8 Reply #4 – June 05, 2006, 09:49:44 PM Well, just leave the 7.5 in until you get more power. Then when it goes you will be more modivated on which to keep. Quote Selected
7.5 vs 8.8 Reply #5 – June 05, 2006, 10:07:07 PM I figured if you were doing Auto-X you wanted a light car. You can easily obtain a numerically higher gearset for the 7.5 and a Traction-Lok (posi) unit for it. Quote Selected
7.5 vs 8.8 Reply #6 – June 05, 2006, 10:22:11 PM I'm in the process of having my 7.5 posi w/4.10's removed to have put in an 8.8 posi. Not sure what it is worth, but it was original to my car when it had a V-6, before I had it changed to posi w/4.10 about 25-30,000 miles ago. I interested in just the rear without the gear, that's cool too. Car is in Owensboro, KY right now. Quote Selected
7.5 vs 8.8 Reply #7 – June 06, 2006, 07:05:49 AM Quote from: Big_DAlso, mentioned two up, 80lbs in weight??? No thanks. I add enough weight when I sit in it:DThat's one of those myths that is never going to die... Yea the 8.8 is heavier, but 80lbs??? NO WAY...Quote from: yellow86coogrI'm in the process of having my 7.5 posi w/4.10's removed to have put in an 8.8 posi. Not sure what it is worth, but it was original to my car when it had a V-6, before I had it changed to posi w/4.10 about 25-30,000 miles ago. I interested in just the rear without the gear, that's cool too. Car is in Owensboro, KY right now.Maybe you could weigh the rears so we'd know the weights??? Say with just the axles installed, no brakes.. Quote Selected
7.5 vs 8.8 Reply #8 – June 06, 2006, 09:04:34 AM There was a thread about the weight difference a while back. I'm doing a search but nothing is coming up. I DO remember that it was marginal at best. Like, 10 lbs or something. Quote Selected
7.5 vs 8.8 Reply #9 – June 06, 2006, 09:05:59 AM That myth will die when I swap my TC rear in, I'm gonna have both rears side by side and weigh 'em both on bathroom scales. I can't see 80 pounds either - maybe if the 7.5 were aluminum you'd see a difference like that, but not iron - hell, the only parts on the rears that are really different are the center sections (the tubes, axle shafts, etc should be pretty much identical) Quote Selected
7.5 vs 8.8 Reply #10 – June 06, 2006, 01:34:21 PM Woo-hoo I found it.http://corner-carvers.com/forums/showthread.php?t=187&highlight=8.8+7.5+differenceSticky this B! Quote Selected
7.5 vs 8.8 Reply #11 – June 06, 2006, 07:29:55 PM Nice job thunder. You guys had me wonderin' too. Quote Selected
7.5 vs 8.8 Reply #12 – June 06, 2006, 08:03:51 PM Nice find. I deem it stickyworthy :D Quote Selected
7.5 vs 8.8 Reply #13 – June 06, 2006, 08:15:21 PM Quote from: darkthunderThere was a thread about the weight difference a while back.Yes, too bad one can't find it via the search. :( http://www.foxtbirdcougarforums.com/showpost.php?p=6727&postcount=18 Quote Selected
7.5 vs 8.8 Reply #14 – June 06, 2006, 08:15:26 PM If you wanted True Posi just weld up the spider gears in your 7.5... that way you don't have to take a chance on getting the backlash perfect because you can weld it up with the axle still in one piece. I could never put in a carrier assembly without it later ripping to shreads. I tried carbon paper and lip stick to make sure the tolerances were correct but no matter what the 5 times i changed the gears they all went to ! Quote Selected