Help deciding which center section to buy

[John510]

My car is a T56 LS3 with a Fab 9 rear and 19x12's. Has a Texas Speed 231/236 cam installed.

I am confised on which center section I should order. Iron or Aluminum? Which brand is best? Id like it to be able to hold some power as eventually it will get a Kenne Bell.

Also, what gear ratio would you guys recommend? 4:10 or 3:73?

Thanks for the help

[funcars]

Cast iron is much stiffer than aluminum and resists deflection better. With drag racing the case deflection is tougher on gear contact patterns and cast iron may be the longer gear life approach. Road racing isn't usually quite as brtutal on the cases and gears seem to live longer with an aluminum case.

If you have mega torque and huge ultra sticky tires the choice is pretty obvious.

[TheJDMan]

This guy sells rebuilt 9" center sections in your choice of gear ratios for not a lot of money.

http://cgi.ebay.com/ebaymotors/FORD-...item4cfac67073

[bulletpruf]

Originally Posted by funcars

Cast iron is much stiffer than aluminum and resists deflection better. With drag racing the case deflection is tougher on gear contact patterns and cast iron may be the longer gear life approach. Road racing isn't usually quite as brtutal on the cases and gears seem to live longer with an aluminum case.

If you have mega torque and huge ultra sticky tires the choice is pretty obvious.

X2.

The only reason to run aluminum is to save weight, but it's not much. Maybe 10 pounds? Iron is stronger and a lot cheaper, too.

As for the gear ratio, google "gear ratio analyzer" for something online. Plug in your trans gears, tire size, and rear end ratios to see what it does to your rpm.

Scott

[Ron in SoCal]

Scott - IIRC, my aluminum cover was 1/2 the weight and about 15 - 17lb savings according to Moser...

[intocarss]

In my drag car, I ran both the N case and the Moser through bolt alum cases. I never saw a difference in gear wear and we checked that stuff pretty regulary and my car was 3050# and made 1000Hp JMOHO