Rear end advice needed

[lemans70]

Hi guys,



Im putting together a pro-touring 1970 Lemans on a budget. I have the full hotchkis suspension including the extreme sway bar and the upper and lower control arms ( plus TVS ) The car had a stock 350 in it and I purchased a 425Hp 400 to install my question regarding the rear end is can I use the same rear end with a locker? its the original 30spline 12bolt with 373 gears. I have already bought the disk brake conversion and wasnt really expecting to buy the engine but it was for a good price so I picked it up. Now my concern is that I will have to replace the entire rear to accomodate the increase in power. Any guidance would be helpful

[Randy67]

Is it the C-clip style (Chevrolet) 12-bolt? I believe so since it is 30-spline? If so, it will handle the 400 with no problems.

[Hotchkis]

Lemans70 – Thanks for installing Hotchkis suspension products on your Lemans! Do you have any images of your car posted?

The factory 12-bolt is probably going to be fine for a while unless you’re going to be taking it drag racing with some slicks. It would probably help to install a heavy duty aluminum differential cover with the bearing-cap pre-load screws.

[badazz81z28]

No offense, but 400hp is not alot of power. Even a 10 bolt can easily handle that. Start approaching 600hp and consider welding the axle tubes to the housing.

[astroracer]

No offense, but 400hp is not alot of power. Even a 10 bolt can easily handle that. Start approaching 600hp and consider welding the axle tubes to the housing.

You have no worries unless you are going drag racing, with slicks, and 100% traction....
What trans are you using? Probably a 350TH. Consider spending the money on a better trans (700R4) as the old 350 is going to be your weak link.
Mark

[Josh]

Just remember that with street driving, the TH350 will probably last forever behind 400HP.

[andrewb70]

For the record, a 1970 LeMans never came originally with a 12 bolt rear. Might want to double check to see exactly what you have.

Andrew