Hey folks. I am replacing the 305 in my 86 with a 388 that is supposed to push nearly 470hp. I am doing the right thing with the tranny build, but have to try and save some money on the rear end. The tranny is all but wiping out my budget.

I have a 'friend' with a 26 spline rear end with an aftermarket Auburn limited slip and 3.73 gears. My question is whether or not this setup is likely to hand grenade behind my motor/trans setup. Oh, the tranny has a full manual valve body if that makes a difference.

I welcome all opinions, but answers supported with data or sound explanations are most appreciated. Many thanks.

 

Without any specs on the actual axle it's self, it's basically impossible to tell.

I'm sure there's no horsepower limit though. Just a torque limit!

But seriously, you'll have to talk more to your friend about this axle. I personally would not take a chance with buying such crucial part of the whole driveline, from a friend, used..

You will be way better off making the sacrifice, and getting something that will work the first time, no questions asked, but that's just me.

 

Don't run anything more than regular radial tires. Not drag radials, just regular, road legal radials.

If you do that you might get away with it.

 

I appreciate the feedback.

I would love to drop in Ford 9", but between the motor, tranny, chassis, paint, interior, suspension, brakes, etc... don't let me get carried away.

Assuming a number of you are married, you can understand that alimony and child support payments are not in my budget.

EternalZ,
The torque number is going to fall very close to that 470 number as well. What kind of additional info can I provide on the axles? Let me know what you need to know and I'll get the information.

Based on his information, they are stock. The only changes made to the rear end were the addition of the Auburn LS unit and switching the gear set out to 3.73s

 

It isn't so much that "Higher #s = Broken parts". It's how you apply it.

You could run 1000 lb fts of torque engine, to a 26 spline axle....If you never run slicks/never drag rate, etc. Remember....Just because your engine CAN produce a high #, it isn't always doing so, except at full throttle, under ideal conditions. The Bugatti Veryon puts out 1001 hp & has an on-board dyno dash read out. On Top Gear the other night, the dash was reading only 52hp, at highway speed cruise.

Slicks are what usually break parts. Street tires generally lose traction & spin, before the parts brake.

 

It defeats the purpose of building a high HP car if you can't get the power to the ground to use it.

 

Is the axle it's self aftermarket? Or stock and put between them aftermarket Richmond gears?

I'd imagine if the actual axle is aftermarket, there would be a serial number, a production name, or at least anything stamped on the axle. Then you could email Richmond, or look to see if they still produce it, and what the power limit is.

 

If he's already low on $ from building everything else....It'll get the car rolling, like to a job, to earn more $, to buy more stuff.

Would it be ideal & final? No. But sometimes you do have to compromise & just be gentler on the throttle, until you can put something that WILL live.

I don't like spending $ on "stepping stone" parts either, but sometimes you have no choice.

 

Stephen, you nailed it on the head. The rear end is a 'stepping stone' purchase until I can get another few K together for a proper set up.

I hate making a throw away purchase as much as anyone, but if that car isn't moving on its own power by October, my wife is likely to give it away. She is not exactly pleased with my choosing to "invest" 15K in an 8K car. Women just don't get it sometimes. Go figure...

Anyway, I will look at the axles for any stampings to get a bit more info. Until whenever, I will just stay out of the throttle in first and second gears.

I am very thankful to each of you for your input.

 

any time my 92 would SNAP the rear end (3 time) it was the pinon.. i would rip the teeth off at the roots.. with a hard Hole shot.. slicks... and about 490 HP.. always babyed it out of the Hole for years... about 7 years of doing that..and 3 sets of richmd gears all 4.11. all aburn parts even the alum preload cover.. all that stuff.. if i did a 1.54 60" time i would kill the gears... then one day after eatting a rear end and tranny sprag and tork converter.. i poped for a $2200.. carri entrprs bolt it 9" with detrt locker 4.11 and N house. took about 1hr to bolt it in.(and 2 days to make it look nice).it was truly a bolt in with my disc brakes even the yoke was for my drive line..

the car will only be has good as it's weak Link.. make it close to Bomb proof.. as you will always want to go faster..trust me..I know

and agen dont look at the Dust