gm7.5 & gm8.5 rear questions

[lilbowtie]

My 79 Monte Carlo has been running a GM 7.5 with a Detroit Locker, Richmond 4.10 gears, Tom's KA 28 spline axles, Summit girdle cover and a 8.5 modified steel cap on the ring gear side for over 8 years on Mickey Thompson ET Streets.
While the 406 SB Chevy and turbo 350 trans.with 3000 stall converter make less than 500 HP, this set up has performed quite well for 8.10 sec 1/8 mile passes in full street trim.
These are the guys I purchased the axles, Detroit Locker, Main Cap and install kit from.
http://www.tomsdifferentials.com/
While its not a 9 inch, This package has given me years of great service.

That 8.10 pass says you are putting out about 320 hp which a well build 7.5 can handle.

 

[bertscova]

http://www.richmondgear.com/2.html

I also found this calculator. It is helpful to figure out gearing for street driving and cruising.

Thanks Garrett192 this calculator says with my wheel size and the 2004r's final gear of .67 i could cruise at 60mph with a 4.11 gear at just over 2000 rpms that would be outstanding

 

[Garrett1982]

Thanks Garrett192 this calculator says with my wheel size and the 2004r's final gear of .67 i could cruise at 60mph with a 4.11 gear at just over 2000 rpms that would be outstanding

Glad to help.

 

[79 USA 1]

couldn't find the prices on the site. I was just curious what was the total cost invested in your 7.5?

At 2004 prices including all seals, lubricant and a new front yoke just over $1000.00. Labor rate for install to Dad & Brother: Do similar install in Brothers 74 Monte Carlo and complete repaint on Dads 89 Grand Marquis. Just got to love the barter system!

 

[Garrett1982]

At 2004 prices including all seals, lubricant and a new front yoke just over $1000.00. Labor rate for install to Dad & Brother: Do similar install in Brothers 74 Monte Carlo and complete repaint on Dads 89 Grand Marquis. Just got to love the barter system!

Not bad. I can imagine what it would be like to get it done somewhere though.

 

[bertscova]

If its a 11X10-1/4 COVER is it a 8.5 rearend