If I fully build my 7.5 rear end Detroit locker gears girdle maybe some beefier axles. Would it be strong enough to handle a 4.2 stroker with a either a m112 or twins?

 

bump Bump BUMP???

 

It depends on how you plan on driving the car. 7.5 will hold up well if your installing quality parts, but any rear end can blow up if your launching hard enough and have sticky tires. 7.5 will for the most part be trouble free for normal street/strip driving. But if you go full drag strip with hard launches then its just a time bomb with who knows how much time till it goes.

If it was me, I would probly just spend the extra money on an 8.8 and beef that up.

 

Not a chance. First off, there aren't a lot of strengthening parts for 7.5. Second, the structure of the axle is too weak to take loads like you describe. The axle's good for maybe 200 wheel, realistically. It's just too small and has too little material. 8.8s are a dime a dozen and easily upgraded.

 

Ya I've been leaning towards getting an 8.8 from the junkyard and building it. Was just curious on how much a built 7.5 could handle. Thank you!

 

The only difference in the 7.5 and 8.8 is the differential. By using a quality diff like a Detroit or auburn. Then you will be fine.

 

The pumpkin is smaller, the ring gear is obviously smaller, the bearings and seals are different. The only thing the same are the axles and you'll wreck those with sticky tire and/or FI, as the op suggests he wants to do.

Not all 8.8s are the same either. 28 spline ones are a goodly amount weaker, say 25% than their 31 spline counterparts.