Rear end upgrades

[Blacky]

The car is now making 600 horsepower and I've had 60 ft of 1.40 and am now nervous that I'm going to break something in the rear end. End. Right now all I have is an upgrade is the mosier 28 spline axles but a friend of mine twisted the heck out of his and he doesn't run as hard as I do. Want to keep it stock appearing so I have to deal with the housing I have. Your expertise would be appreciated. I'm sure many of you have found out the hard way as we always do and I'm just trying to avoid that

 

['87 Turbo "T"]

If I were you & don't want to go Ford 9", the biggest you can go in the stock set-up is 30 spline.

You'll need a new carrier but you can eliminate the "C"-clips, get a your choice of gears(if wanted), choice of locking(Tru-trac, Eaton etc), your choice of axle manufacturer, etc.

Of course we know the launching 60' are what put the most stress on the axles. I have a guy that can do them. He blasts re-paints, puts your choice of axles, locking diff, etc. in. He's in PA.

 

[hensleyt]

I did a Mark Williams C-clip eliminator it sits on the axle housing instead of the bolts. and is steel not aluminum. I had a 28 spline True-trac already but if I did not have a 28 spline Tru-Trac and axles I would have sold my 28 spline Moser and gone, 30 spline Tru-Trac Mark Williams axle (1.625 OD) and his C-clip. Moser dose costume the 30 spline with the big bearing surface for the big Ford bearing 1.625 instead of the 1.400 shaft . I'm just 500 hp, and can live with what I have. But my friend you can sale your 28. go 30 and look at and call Mark Williams. Almost as strong as a 9 in less power lost through the drive line no funky back brake combo. if you see 800-1000 hp in the future ditch the 8.5 and go 9.

 

[Pronto]

My friend and I went with Strange Hybrid axles in 30 spline, Eaton Tru-Trac and Strange c clip elims. We welded the axle tubes. My buddy also added some U channel to the tubes too. Also did the Strange billet yoke and there driveshafts with billet yoke. The Strange items were of very high quality. Welds on the driveshaft were superior. Everything runs very smooth. Smoother than the stock setup in fact.

 

[Blacky]

A lot of good ideas from a lot of experience. People are starting to come in. I think I'm leaning towards pronto set up as it seems like it would be exactly what I want along with the stronger drive shaft. Now I have to find somebody that can do all the work in the Cleveland area. If anyone has a local shop in my area let me know. I've heard of one and Erie PA which isn't horribly far from me.
Thanks members

 

[Pronto]

We also did new gears that we had polished at NE Gear Polishing.

 

[Blacky]

Pronto? I'm not sure what that means by polishing the new gears. Does that make them stronger or something? And what gears, the tru track ones? I've put the new axles in mine years ago and changed out the pin to a newer one but other than that I'm green

 

[Pronto]

https://negearpolishing.com/

https://cmgearworks.com/

We got AAM ring and pinion gears and their master rebuild kit. GM8.5HD and 40053029

 

[Pronto]

Cutting the tube ends was a pucker factor but once the cutting starts there's no going back. Drilling the flanges was also a chore. Buy yourself some super high quality bits. Mine started to give out after 5 holes and that was using several sizes to step up. I bought extra flange gaskets and used them as a double check for the holes. If you have a differential shop do it then they should have a lath to drill the holes for the elims. It ended up costing as much as a 9 bolt conversion but the rear is strong as I'll ever need. Also there is no parasitic draw from a 9 bolt config + the there is a weight savings over a 9. Everything else ie; yokes, driveshaft you'll need anyway. In the end they probably cost about the same. If I was going for a track only car then I'ld do the 9 or 8.8 Ford.

 

[hensleyt]

If a good differential shop dose the work you should be good. as soon as you weld any at all on the housing it will get as crooked as a dog back leg.
If I decide to do any welding on the housing and do a C- clip elimination I would do this

7900 - Small GM Car Housing Ends (uses 9" Ford large bearing & non c-clip axles) from MOSER​

a 30 spline axle is just 1.400 OD at the wheel you gain size at the diff but remain just 1.400 at the wheel, it is bigger than the 30 count spline but 1/2 ton gm trucks use the same 30 spline axle wheel bearing is 1.618, .200 bigger than the GN 1.400.
Moser Curie Mark Williams all use the Ford big bearing assembly for big HP even in the 8.8.
Im long wended about this to help you not make the same mistake as me. But I do not see a 750 hp in the future but I do have enough parts to build a 3.8 or 4.1 that can make that along with a transmission to support it.

 

[Pronto]

My buddy and I had no issues with warping. We did it the right way by heating the pumpkin to 500* and then welding with 55% nickel. Wrapped it with a welding blanket and let it slow cool for a day.