lurch59

I was wondering how many on the forum have Tom's 12 bolt diff and the very heavy duty 1480 kit (1480 u joints, 3 1/2" half shafts, 30 spline inner axles and 31 spline outers)? Has anyone broke anything and if so, how did you do it?

ajrothm

I don't have the 12 bolt stuff... But I do have Toms 30 spline inner axles, 31 spline outers, 12 bolt spider gears and cross pin etc... Basically a super 10 bolt built by Mike Dyers with Toms stuff, I haven't broke anything yet, that's with over 80 mid to high 10 second passes... However my car is an auto so it's much easier on parts.

Toms has good stuff for sure...but $$$$

69ttop502

I have the same super 10 bolt as Alan, currently being done by Tracdogg here on the forum. I also have the 1480's. Didn't do the 12 bolt because I wanted 3.08 gears and 12 bolt is only 3.73 and up. Great stuff. Didn't kill it with my 614 horse 502 and 4 speed. No racing but I beat on it.

73BLWN

I've got the whole package as described. I have a 671 blown 400sbc 722hp, 686trq. Mike took care of me. It's a solid setup for sure. I'm in the process of fitting a bigger tire, but my 275/60/15 Mickeys hook well, and reportedly pull the front tires on the street. I drive it hard, and don't worry at all about breaking parts. So far so good.

lurch59

You and I have similar engines built by Mark Jones. I spoke with you on the phone to get some advice 2-3 years ago, the car is done now but I have a stick so I went a little beefier....my wife saw me doing a burnout last weekend and she said "you're going to break something!"

I told her "I don't think so!" I am gonna try though

Thanks for the feedback..

lurch59

Do you have overdrive? Mines a 3.90 gear with 0.64 overdrive, even with that combo RPMs a little high at 80 mph. Thanks for the reply.

lurch59

Hmmm, interesting. Stick or auto? I have similar hp/tq numbers. You are obviously hooking!

SteveG75

I have the 12 bolt setup with the 1350 joints and 3.73 gears built up by Gary Ramdei. 496 BBC, T56 Magnum. 413 rwhp.

No issues so far. Figure the 1310 and 1330 joints in my driveshaft are the weak links.

gkull

I a home built 10 inch with two gear sets, one Richmond and the other US gears.

I have custom hardened yokes from Mid America. Toms stage 7 posi unit, billet main caps, HD rear cover, 1350's and tom's outers.

i always expect something to brake any moment, but it's all about 12 years old. with my TKO 600

69ttop502

I will be running a Richmond with 1 to 1 5th gear. Upping the power and just feel more comfortable getting my overdrive from the rear gears.

lurch59

Yes the driveshaft may be the weak link, but the torque multiplied to the half shafts are much greater than the torque transferred by the driveshaft. I don't know the answer to that one...

lurch59

Lower driveshaft and rear gear RPM's, it has it's advantages.

lurch59

And if I remember correctly you are running a lot of horsepower so that is a good track record.

Richard Daugird

I was under the impression that Tom had died and after existing stock is gone, it's gone for good.

lurch59

An Employee in Tom's shop passed a few years ago, and that is why he quit assembling differentials. But you know how internet rumors go....I don't know about Tom himself.

I've also heard that the supply of Tom's parts is limited and there will be no availability in the near future. Another rumor but from a reliable source. This may mean he is retiring and the business will not carry on.

69ttop502

Give Tracdogg a call. He has all the real info when it comes to Toms differentials parts. He had no trouble getting parts for my build.

SteveG75

Word I got was that Tom was having trouble getting tool steel spiders and refused to use powdered metal Chinese gears. Supposedly, I got one of two sets left at the time my diff was built. Maybe he has managed to source more since them.

Unfortunately, many people are willing to save a little $$ vice pay for made in the US quality parts. It is evident in most of the aftermarket parts suppliers.

73BLWN

I'm running a American Powertrain TKO600 5spd, 3.73s, .64 od, Fort Wayne 2 3/4" driveshaft 1350 u-joints. I like banging gears. If you are running smiling numbers, i would suggest you upgrade to match your post if you haven't already. A solid axle coversion would be cool too, but I like maintaining the classic independent suspension.
I'm also curious if anyone has hurt the Tom's 1480 setup. If so how, with some details.

tracdogg2

To my knowledge no one has hurt the 1480 set up.
The 10-17-30 cut gear spiders gears are all but gone. Maybe a dozen sets left. There is one other option that I am testing.
Tom is healthy as can be but he has retirement in his sights. Most likely the 12 bolt stuff will still be available even if Tom does retire but there will be a lot of machining required.
Toms aluminum 12 bolt housing isn't dead yet.
1310 u-joints are stronger than 1330's unless they are the spicer solids. Then they are the same strength.
Tom is discontinuing the 4340 steel spindles and stub axles.
I believe Angelo Valla ran Toms 12 bolt in his 72. Mid 8 second car.
Snowman runs the 12 bolt 1480 set up I built for him. 860 hp 555 T-56. No problem pulling the front wheels.
632C2 runs a 12 bolt 1480 that kenny built. I believe he was around 1400 at the rear wheels. I built him a 12 bolt 1350 for his other vette.

The two biggest causes for diff failures are cap stretch and improper posi clutch set up. The main difference between a Super 10 and a 12 bolt is the thickness of the carrier. Everything else is near the same. The ring gear and carrier are larger and require quite a bit of machining inside the housing. Others use the drop and gouge method to clearance the housing. I prefer to bore the housing. Much cleaner and more consistant.
Corvette iron diff housings probably have the worst machining known to man. Uneven pad heights, bearing cap bolt holes drilled off center, bearing bore depths uneven, and misalignment of the pinion to ring gear on the later housings. Only one worse is the 80-82 dana 44 corvette housing. To my knowledge i am the only one machining these housings to the carrier centerline.
Right now Pauldana has the very best Super 10 built. But Bill's (69ttop502) is going to surpass it. I am doing a full picture documentation of his build including modifying the Ridetech suspension to use the 1480 set up. Bill knows firsthand the best parts installed wrong means doing it all over again.
Mike

slofut

I talked to Tom about 6 weeks ago and he was fine, just grumbling about being tired of it all! Can't blame him

He said he was retiring at the end of the year come hell or high water and I got the last pair of axle loops he had.