Rear end and gear suggestions.

[347strokin]

Hey guys,

I'm in the process of building up an LS 6.0 around 450hp at the wheels. This is going in my 87' 2wd Square which currently has a 10 bolt rear. Trans will be a 4L80E.

I'm running on 245/35/20 and 295/35/20 rubber.

Truck will be a daily summer driver that will see highway half the time.

What gearing would you recommend?

Can I just bolt in a 12 bolt and will it be strong enough?

What year 12 bolts fit our trucks?

Thanks!

 

[Driver4r]

Befor they went to the corperate 10, they had a 12 bolt under the back of them.

Other options would be a leaf sprung 9"
Ford 8.8 (exploaders etc....)

 

[74propu]

I am running a 10 bolt posi in my 74 that has been in it for 6 years 3 years with a 496 twisting the **** out of it and now with a 5.3 twin turbo 560whp twisting it and it still is holding up . Gear is 348 with 33x18.50 r 15 tires m/Thompson .

 

[HotRodPC]

You can get a 12 bolt out of an older square, but it's really a non issue. The truck 12 and 10 bolts are different from passenger car 10 and 12 bolts. In the passenger cars, it's true, the 12 bolts are stronger than the 10's. In the trucks, there's not much difference. In fact, the 10 bolt truck is stronger in one area than the 12 bolt and the 12 bolt is stronger in another.

With that being said, I think I'd go ahead and make your 10 bolt work the way you want it to. Maybe a gear swap and a Detroit Locker and run it. If that don't hold up, then I'd just consider swapping to a Ford 9in or maybe one of the 14 bolt Semi Floats from a 3/4 ton.

 

[crazy4offroad]

I would have to second the F*rd 9". The pinion pilot bearing will help exponentially with the deflection that much hp will produce. 3.73 will be an OK ratio to put your highway rpm around 1800-2000 but if that won't work well with your cam profile you may need to go 4.11.

 

[jetman]

My experience w/ the 10 bolts is that they are deceptively rugged. If you don't get too rough with it you should get good service life. As stated going from a 10 bolt -> 12 will not get you much more hp capability. Brakes will be larger, if that is of interest, but unsprung weight goes up quite a bit.

The Ford 9" is a good choice if you want to do something. I'd only go with the heavy 14 bolt SF for serious offroad or heavy trailer hauling service.