Technical 55-64 GM 8.4" axle Specs/Info request

Does anybody know the specifications (i.e. horsepower & Torque ratings) of a 1956 passenger car axle? More specificly, will it hold up to 550BHP / 430ft.lbs.?

 

Only if you use bicycle wheels on it.

Pat

 

Chevy 8.2 from 61-64 is the strongest. Put in heavy cars with 425 hp and 4sps. Lots of breakage with slicks. Axles twist/17 spline spiders break, left bearing cap will split, pinion will climb the ring gear when the axle tubes flex forward (in that order). All this can be addressed, but it comes out cheaper and much more durable to go to the 9" made just for you chassis.

 

....or use an early 60s Olds/ Pontiac rear if you want the car to "look right"

 

here's some upgrade info for ya, scroll down until you see it.
http://www.bruneauperformance.ca/camshaftspringsrockers.html

 

Save yourself all the grief & go with 9" or Dana 60. If you are after the period correct look 59 -64 Olds. Pont. setup ,but those are getting into big $$$ . I.M.H.O.

 

Yes, the weight of the car, tire choice, and tranny type will play a roll. also, what gear ratio (the pinion gets really small on the steep gears). To address the axles you can use 8 3/4 mopar side gears. later cases had reverse thread bolts holding the posi cases together and were less prone to coming loose. As others have said - some work to get it to live and if plans are for a stick and sticky tires do youself a favor and upgrade now

 

It will not hold up to a 427 in moderate tune.

 

I know for a fact even with the light weight and an automatic, a mild blown 350 in a model A will wreak havoc on a Tri 5 axle. Popped a posi open and broke a cap, knocked teeth off the gears on the next one. Another buddy let his kid drive his '55 (4 speed 300 horse on radials) for a while, went through at least 3 posi third members from the stash before finally wrecking it. Don't know how a 409 Impala could have been raced regularly with one back in the day. Maybe they were just gentle with the clutch or just years less metal fatigue?

 

8.8 later model Ford Exploder axles are strong as hell and cheap !! Moser will pull out one axle tube and put in another and supply a correct length shaft to get a normal looking centered pinion, all for around $200.00. That doesn't include shipping but I'm sorta close.