Any Chevy gurus out there know why GM used such a difficult-to-upgrade non traditional rear end design with the weakly T5 transmission?(besides cost!)

The drivetrain layout seems too close to a Saginaw 4 speed spindly rear end Monza I had in the 80's.

If I want to put a street carb'd 400 and keep the manual trans, it's T56 time with a $2500 9" or 12 bolt eh? Jeez.

Thanks for any old trivia on the above.

'88 IROC-Z28 T5 LO3 Vert w/imminent 400sbc swap (with missing straight across 3rd starter bolt hole drilled for 153t 400 bal flywheel)

because,they already had the design(monza)AND because it was......CHEAPER to build

the TQ arm set up is not expensive to upgrade, and it flat out WORKS. but yes the 10 bolt rear end is weak....

s60 is yet another choice

Torque arm rear suspension is very versatile. You've got people drag racing and autocrossing with the exact same suspension, not even only teh same design but the same car without changes and having a blast at it.

It would be nice if we had a IRS with the pumpkin on a transverse leaf spring setup like the Corvettes, but that's too expensive for a pony car.