Austin-Healey 100-6 rearend strength

[Shamrock]

I have the new frame and rear suspension installed now in trying to figure out if I should rebuild and use the factory rearend or go with a traditional  8.8 or 9 inch. Im interested in knowing if the factory rearend can handle the horse power increase of a small block?

[kstevusa]

Maybe mention the specific engine you have in mind.  Small Block is a wide variety of engines?  We could get a better idea of the durability you need.  Personally, I have no idea on the Healey strength.  Someone else wil chime in later with more info.

[Shamrock]

Ok..your right . I haven't figured out what type of small block yet,   I have a V6 with a turbo sitting in my garage but I also have axis to a ford 289 hipo motor . I figure they both make just under 300 HP , so maybe I should just talk horse power figures.

[88v8]

The 100-6 produced 140lb-ft.
The 3000 made about 170lb-ft.

The hipo would make around 300lb-ft.

The factory axle might survive behind an auto box if the wheels aren't too wide, the tyres aren't too sticky and the driver isn't lead footed, but unless you're making a resto rod I'd be inclined to sell the factory axle and go with a 9 inch.

Ivor

[Shamrock]

I belive your correct.  I think a 9 inch will be my next purchase

[DiDueColpi]

Unless your Healey has a pickup box on it, a 9inch might not be your best choice.
It would definitely be unbreakable, but there are lots of live axles out there that will handle the power with out doubling unsprung weight.
Having to tame an excessively obese rear end in a light car is a bitch.
For me, something in the 8 inch range would more than accommodate the power and tire that you can fit into that Healey.

Live like you mean it.
Fred

[roverman]

8" Ford can swallow 31 spline axles, with matching carrier. Aluminum center section available.

[HealeyRick]

I think a lot will have to do with how you intend to use the car and what kind of wheels and tires you are going to run.  I have a 345 hp SBF with a stock rear end.  I also have 72-spoke wire wheels with 185-15 tires and seldomly do smoky burnouts.  The tires are going to light up before the axles break.  If you use wide sticky tires and do clutch dumps or drag racing starts you're going to break stuff.  Otherwise, you'll be fine with the stock set up   That rear end is pretty tough   Racing Healeys in Europe regularly run stock rear ends and 300 hp.

[Shamrock]

This is why I come here for the info I need,  it's great to have people around that have eather done it or know so much about these cars.. I'm getting the impression I'm being to vague about the motor I'm putting in but I have so many options I'm not sure yet.. Thanks HealeyRick.. I really like your post , you basically answered questions I haven't asked yet. I want to run wire wheels still and I feel I need to run a rearend with a carrier that opens from the front.