I drove a heavy-haul wrecker built on an Astro with an 8V92 Detroit and a 13-speed Roadranger. Good rig, minimal problems, and it could definitely pull a load. I think the 8V92 was rated at 430 HP, or something like that.

Like with all Detroits, I just needed to slam a couple of fingers in the door first thing in the morning, get good and PO'ed, and drive it wide open all day! A lugged-down Jimmy won't pull a greasy string out of a cat's behind!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!