79 elcamino rear end?

[captjohnie]

I am building a 79 and have built a 300+ HP motor with a rebuilt 350TH transmission with some upgrades to the shifting,my problem is it still has the 7 1/2 inch rear end and with that much power there is no way that I can take it easy on it to save the rear so it has got to go, the question is what rear will work with out breaking the bank and what all will I need to do it [what will fit the best] 8 1/2 or a 9 inch ford? I understand a 80's model mustang will fit? if so what will I need to hook it up rite and I need it to be a posi. or limited slip. just need to know what I need to get it done correctly thanks

 

[O. D. Showtime]

Don't be too hard on that 7.5. We rebuilt the 7.5 rear in my son's 81 Malibu...stuffed in an Auburn posi unit with 4:10 gear. Motor is a 355 dynoed at 375 horse...he's been beating on it for about 3 years now with no issue. Trans is an old TH350 I had with a 2500 stall and very firm shift kit.

 

[captjohnie]

Don't be too hard on that 7.5. We rebuilt the 7.5 rear in my son's 81 Malibu...stuffed in an Auburn posi unit with 4:10 gear. Motor is a 355 dynoed at 375 horse...he's been beating on it for about 3 years now with no issue. Trans is an old TH350 I had with a 2500 stall and very firm shift kit.

thanks will consider that, trying to get it finished up in time for our annual car show at the end of April so may have to go with the 7.5 for now.

 

[565bbchevy]

I did the same with my 7.5" years ago, I installed an Auburn posi with a 373 gear and ran that behind a healthy 496 big block and it still worked fine when I sold it years later after buying my 9" rear.
You can send a lot of power to a 7.5" it is when you start trying to make it hook that it will show you its weakness but in a strictly street car without slicks it will probably last years, you can even install a support rear cover to add some strength.
Also there are no Ford cars that have a direct swap rearend without a lot of fabrication to make them fit but the aftermarket has plenty of bolt in housing/axle set ups all the way to fully assembled complete rears that are ready to install including brakes but these are all very pricey options.

 

[captjohnie]

I did the same with my 7.5" years ago, I installed an Auburn posi with a 373 gear and ran that behind a healthy 496 big block and it still worked fine when I sold it years later after buying my 9" rear.
You can send a lot of power to a 7.5" it is when you start trying to make it hook that it will show you its weakness but in a strictly street car without slicks it will probably last years, you can even install a support rear cover to add some strength.
Also there are no Ford cars that have a direct swap rearend without a lot of fabrication to make them fit but the aftermarket has plenty of bolt in housing/axle set ups all the way to fully assembled complete rears that are ready to install including brakes but these are all very pricey options.

thanks for your input I will consider it car is not painted as of yet, (long sad story) and am trying to get it prepped now so I have a little time on the rear.