Lets see, you have a cast aluminum cover that has a threaded hole through it for a preload bolt pushing against either a cast steel cap or a forge steel after market cap trying to limit distortion on the cap Which one do YOU think will move first, cast aluminum with the preload bolt through it or the cap
My current bracket car came with a LPW cast aluminum girdle on it, I replaced the pro 5.86 race gears that where in it with a set of used Dana Corp.. OEM Ford pickup 4.56 gears, I didn't have issues with the Pro gears except my poor little bracket motor had its tongue out a the 1000 Ft clocks in the 1/4mile with the 5.86 gears. I haven
t had any problems with that girdle or either set of gears so maybe they are helpful The stock Dana 60 rear end housing is really narrow and it has a 4 link coil over rear suspension with Mark William gun drilled 40 spline axles with 5/8 inch wheel studs on them, the current motor doesn't make a bunch of power or torque(maybe near 800 HP and close to 700 Ft. Lb. torque at the flywheel)
The car weighs 2800 Lbs. with driver with a best so far of 8.863 at 150.5 MPH in the 1/4 mile, aiming for quicker and faster this year