[aknassassin]

So i'm almost done with my rear axle swap with my '69 GT and the '78 Buick OPEL by Isuzu rear that i got from a local junkyard. Its turning out pretty darn good I have to say. Nothing real hard, swapped out the brackets from the GT axle, welded them to the Isuzu. Ended up having to grind the Isuzu torque tube brackets on the sides and hammer the tunnel a little to get it to fit up there(didn't think that far ahead or I'd have used the GT torque tube instead). All in all, it should be on the road tonight, i'm stoked grandpa was the last one to drive the car, I helped rebuild the engine but this will be my first time driving it.

 

[spdkilz02]

will this rear end hold up to alot more HP then the factory one?

 

[aknassassin]

I'm not sure about strength in this new axle. I'm pretty sure that its not going to be much stronger. It doesn't have the weak C-clips holding the axle shafts in, so that might be a positive side of it. The axle itself is very similar to the GT axle, the torque tubes are exactly the same, its something like 3/4" wider, the drum brake cyliders are 13/16 (bigger than GT) and this axle has far less miles on it than my old GT one. So in that sense its stronger. Someone else will have to but in on this one because I've not even been able to find info on what the gear ratio in this axle is.

 

[RallyBob]

Someone else will have to but in on this one because I've not even been able to find info on what the gear ratio in this axle is.

I think it's a 3.45 final drive (basically the same as the Opel 3.44). It should have the same overall strength as an Opel rear axle, since the ring gear diameter and differential interchanges with an Opel. The only potential saving grace is that we can *hope* that Isuzu's side gears and spider gears were heat-treated to a slightly lessor degree than Opel's. Opel side/pinion gears are very hard and therefore extremely brittle...they shatter in fact.

Bob

 

[aknassassin]

Thanks Bob, i'll cross my fingers and hope that they weren't heat treated as much. For now though, i just drove it and when you go from a car that won't roll to one that drives down the road anything is a miracle.