Well, after my most nasty divorce I got back into my cars again, and my Coupe has been my focal point the last year.
Roughly 3000 pounds, 650 horsepower 650 ft lb stroker EFI Hemi. 4.10 gears, 727 auto with a PTC 3000 stall. STREET CAR that will get beaten and hit the track.
Has a 742 case right now, I'm thinking of an aluminum center section, I have load bolts going through my back brace to the rear of the caps.
ProTrac S515 street tires mostly in store for the car.

Do these aluminum cases have relatively no problems if used in lighter (under 3000 pounds) cars? Has anybody put lots of miles in a street car with them? I'm about to pull the trigger, any input appreciated. I'll post a pic of the diff so the "load bolt" part is easier to see, I'm trying for reliable quick street car that isn't a trailer queen and will hit the track a couple times a year....

Anything I should be made aware of?
Thanks!!!

Diff housing. Backbraced with load bolt provisions, thought I would try everything I could!!! lol

Welcome back.

I believe Mike/Mr. P Body ran one for a long time, he should be able to advise how it held up.

The main historic problems with the part were price and availability.

Though I'm not employed there anymore I am pretty sure P4876445 is discontinued/obsolete/NS1.
Maybe have someone look in dealer connect and see, before trying to head down that road.
If you don't already know where one is, it could be hard to find.

Thanks Zippy!
I found a new one, it's $1300 Canadian, which is about $1000 US, and I'm not thinking the 11 pound difference is a big thing, but if it's a bit stronger I don't mind trying it. 650hp and 3000 pounds, footbrake car on street tires. I want to TRY to make an 8 3/4 work in the car!!! lol

Is that a threaded slug going thru back brace and rear end housing? I have an old chromed 8 3/4 housing out of a dragster that looks a lot like yours. Nice work. Jim.

No way any aluminum parts, no matter the alloy and heat treating are tougher than cast steel like the Mopar third members are
On your deal I would call Mark Williams or Dr. Diff and buy a steel cap or two and install them on your 742 case
I've use them and they help a bunch on racing 8 3/4 by extending the ring and pinion life

Thanks Bandit. Load bolts straight to the back of the caps. I want to try to address every known weak point as best I can.

Oh I know you are a smart cookie....
I thought of MW caps backed up by load bolts. I thought of a Nodular case with the MW caps. I know the aluminum case is overpriced in many eyes but claims of 10% less deflection and stronger caps has me thinking of trying it.

Would not bother with the aluminum piece, especially for that money. The case is usually not the weak point anyway. I've fooled with a few of those in the past and didn't particularly care for them. Bearing bores were tight and some other issues IIRC.

Nodular iron 489 is available all over for less than $300. That would be my choice.

Actually my first choice would be a 9, but that's me. Second choice for your 8.75 deal would be an aftermarket case and housing, but then you're still stuck with the gear options - or lack thereof. Leave the old OEM stuff for the restoration and stock chassis guys.

My Demon had a 9", never want to go THAT route again.... geez!!!! It taught me Ford 9" rears are good so long as everything "Ford" is removed from the center section!!! I have a 9" in a brandX car, the center cost a lot more than a couple of MP aluminum housings!!!

I might still try a Nodular, but the 8 3/4 rear is going to get a tryout for sure. I've always had good luck with them. Knock on wood.....

Chat with Doctor Diff. He knows a lot about those housings. He might have his own housing out now, not sure if he made it happen or not.

Mopar syas the new Alum is 10%? stronger then stock. There has been a new one on ebay for the past few weeks in the $4K range. Decades back before Mopar finally got around to offering an alum solution, I negotiated a deal to buy an entire rolling dragster with a MW alum 8.75, just to get the rear end.. Seller eventually felt sorry for me and just sold the rear, which I have today. I have a few Mopar alum rears, and a new one in the boX. The rears wiill not accept anything lower then 3.23 w//o some internal clearancing. When I saw the new $4K street price, I hesitated.

If you found a good/new unit for $1K, I suggest buy it, if only for investment, as they are never going to make more. .

I think he didn't like them, thought they were overpriced. I remember replies about 10 years? ago. They went to $900 and everybody thought wayyyyy too expensive.

I found one brand new for $1300 Canadian, about $1000 us. I told my buddy to grab it so I'll know tomorrow. Wouldn't mind trying it anyways!!! My car is 4.10 gears

I bought one about 15 years ago or so - before the new nodular casting was available The rear end was in an 86 charger and the housing was about 22" inches wide - The aluminum center section was huge pain to set-up - you had to heat the thing up in the oven to get the bearing races in - it was a big chunk of aluminum and like mentioned supposed to be 10% stronger. the price back then was around a grand and really was not worth the bang for the bucks. For the weight of car you are planning on - I would not hesitate to use a stock or a nodular casting especially with that back braced housing.

My housing is 35" wide. I'll give the 8 3/4 a chance, see how it goes, I would toss a Dana 60 in it if it has more than it's share of troubles, but I got my fingers crossed.... The big thing with these aluminum center sections seems to be the price, and I agree it's terrible bang for the buck, but I think I'll try it anyways. I just am trying my hardest to make an 8 3/4 work, and it's not big power- 650hp/650 ft lbs, and it's around the 3000 pound mark, it's an automatic I am NOT using a trans brake, and 98% of the time it will be street tires..... Will see I guess. Maybe the center section won't show up!? lol

I appreciate the input.

Been running the Dr. Diff for a few years now and love it......it's a bit heavier but well braced......

CRaZy ... is that 650 Canadian or USA horsepower?

I've been running the alum case for years without ANY issues.. twisted up one set of axles but
the case was perfect.. all very hard launches

US horsepower. If Canadian horsepower the conversion would bring it down to 497 horsepower but after taxes here I would be left with nothing.....