How much hp/torq will an OEM 833 4sp and 8 3/4 take?

American Metal Direct (AMD) has finished converting my 69 M-Code Cuda from a drag car back to original factory construction. (see general discussion thread, "My M-Code is finally getting worked on.")

M-Codes were factory 383 torqflite Barracudas which were converted to 440's by the Hurst Corp and sold as "factory cars." mopar only put torqflites in the cars because they thought a 4 speed would either not hold up or would be abused enough to cause too many warranty claims. however, they did install the same 8 3/4 rear diff that all the Formula S and "Cuda package" cars came with.

the "standard" 440 that Plymouth put in the GTX in 1969 was rated at 375 horse and 490 lbs. of torq. but that car (and the A12) came with a Dana 60 rear end and the "Hemi" 4 speed. the A12 440 six pac motor was rated at 390 hp and 490 lbs. of torq.

i want to build the engine and drivetrain on my car the same as the A12 69 1/2 Roadrunner. however, a Dana 60 is a couple of inches wider than the 8 3/4 that came in 340, 383 and the 440 Barracudas. so i would like to use the 8 3/4.

so here's a couple of questions that i'm hoping someone in the FABO racing community will have some knowlege on..

1. will the "short" 833 4 speed that came in the A-Body Barracudas stand an A12 440?

2. will an 8 3/4 with a 3:91 posi stand an A12 440?

the idea of the car i'm building is to build "the M-Code that Plymouth should have built." the car will be a 440 six pac built to A12 specs with a 4 speed and a 3:91. i am not building this car to be a regular drag race car but i suspect i will race it a few times. i'm wanting to be able to smoke the tires at around 3500 in first gear and "power shift" second at about 6k.

what do you think ... will i "break" this car the first "vintage drags" i take it to?

thanks...
jim coster
pittsburgh, pa