I'm helping a friend (actually business manager who runs my repair and motorsports shops) rebuild a 4L80E which will behind a supercharged steel-block 6.0l LS1 in a Fox-body Mustang.
If we are aiming for 1000 Crank HP, is a billet input shaft recommended? What about output shaft? If not yet, at what HP/Torque are they recommended?
I've heard that nitrous is harder on shafts than super/turbo-charging, but even constant torque will eventually break a shaft. BTW this will be a 95% street car.
@FranksCustomTrans Frank hooked me up with his recommended rebuild and performance kits for this trans, but didn't go as far as billet internals.
Thanks guys.

 

The ONLY question you have to ask your customer is:
" Do you want to FIX it before it breaks... or AFTER it Breaks" ?

 

IMO you don't with a 2800 LB fox body. I mean great if your bucks up and can . I tend to overbuild for my own stuff .My Impala with under 500 rwhp Has my stage 3 60e build.
To me its all about budget , If I had the surplus cash sure, If not I would spend the money on something to make more power or with fox body suspension.
I have seen the 80e stand behind 5000 pound trucks with 800 at the wheels with little more than a shift kit.
Just my thoughts each to their own of course.

 

Yup, I already told him that. I conjectured that if it breaks, there likely wouldn't be any other damage. (Assuming rev limiter works fast enough.) Or would there be other trans damage?
Dropping a trans just isn't a big deal for us. (Or we just ask one of our mechanics to do it. <grin>)
He saw prices of $1000 per billet shaft which seems high; the billet shafts in my 4L65E were about $500, but that was maybe 10 years ago.

 

At 1000HP, I recommend a hardened input shaft, intermediate shaft & a HD fwd hub. I dual feed the direct on most 4L80E's I do....
Transmission specialties is good for those parts.
Jakes has them too, looks like the 1000hp input shaft is on sale.
https://shop.jakesperformance.com/sh...-upgrade-parts

 

Thanks @Transman for the link to Jake's stuff. We will order the parts you suggest.