Stainless Exhaust

[mfg]

I just yesterday bought a stainless steel exhaust system through Dave Thibeault. Can't believe the difference in the weight of each pipe compared to mild steel! This exhaust system, and a change back to my '63's original 3.54 TT rear end, will be this year's 'improvements'. I installed a 3.07 rear gear several years ago for an easier highway cruise... but I now don't think that was a good move....the 3.07 really seemed to kill the car's 'low end' (even starting out in 1st) (Auto trans.)

[mfg]

Just today removed the cover from the TT differential I'm re-installing in My '63. I thought for sure the ratio would be 3.54-1, but the numbers on the ring gear are 43/13, which divides out to 3.31. That's OK... it's still a good alternative to the 3.07's that are in the car now. (ratio tag under cover bolt was missing, although limited-slip tag still there)

[StudeNorm]

I was thinking of swapping the ring and pinion from a 3.31:1 tapered posi rear end for the ring and pinion from the 3.73:1 non-posi rear in my car now. This idea is just in the in-box and hasn't yet been researched as to feasability...

But then again if I install a T5 or T56 the 3.73's will be the gears of choice.

I find the 3.31:1 gears about the best compromise if you don't have OD. You will probably be happier with them.

Depends how you want to go.

[Charlie Kile]

Tell me something I don't know or fully understand.

Mine is an 84 Touring Optioned Coupe. RQB3921, 2:86 twin traction final drive, 700R4 OD trans with lock up, and the engine is a stage 2 Jasper with TPI.

I can't imagine going to lower ratio rear end. As it is, I can smoke both rear wheels with a full throttle start, and still get over 24mpg on the highway.

So what can you possibly gain by going to the 3.31, or 3.73 gears.

I would think that it would be hard to control with a hard take off.

With both wheels broke loose mine is hard to keep straight.

Charlie RQB3021

[mfg]

I think that the 700R4 has a very low (high numerically) first gear which would account for smoking the rear tires with that sky-high 2.86 rear. The Studebaker Avanti Powershift's first gear isn't all that low. If My '63 had a 700R4 in it, I'm pretty sure I'd be leaving the 3.07 in place. My '83 Avanti has a 700R4 with the 2.86 rear....and it does seem to accelerate very well. The 700R4 is definitely a nice transmission to have in an Avanti!

[Gunslinger]

My '70 Avanti with a GM Performance 350 HO 330hp crate engine with a 3.31 rear and a 700R4 transmission takes some feathering of the throttle to move out without spinning the tires. The engine power, the low first gear of the 700R4 and the front weight bias of the car make it all to easy to spin the tires.

[SBCA96]

Yes .. The gearing on the Powershift (1st gear of 2.40 and 2nd of 1.47) is "high" in comparison to the

700r4 (1st gear of 3.06 and 2nd of 1.63). I used a 3:31 TT in my Hawk with a 700R4 and it was quite

a nice combo. In my wifes 1978 Camaro we are running 3.42 gears which feels pretty low. The 3.31 I

used in the Hawk was swapped into the Avanti which now has a TKO 5 speed rather than the original

T-86 3 speed I hated. Install here :

http://forum.studebakerdriversclub.com/showthread.php?8204-Studebaker-Avanti-TKO-5-speed-install-how-to

Tom

[mfg]

Just wrestled the 3.31 TT rear end assembly into My '63. These units have definitely gotten heavier over the years(!!!). I made up some 1/16" rubber 'pads' and placed them between the top of the leaf spring and the rear axle mounting 'perch'. Studebaker installed a 1/4" thick pad between the bottom of the leaf spring and the shock mounting plate, but nothing at the top of the leaf spring. I figure a little extra insulation wont hurt!.....Now onto the install of the brake backing plates, and setting of axle shaft end play!

[mfg]

Took the '63 for a road test with its new (old) 3.31 TT axle.....and I really like the way it now moves out in 1st. The 3.07 was just too 'tall' for me. Also, I didn't really notice a much higher RPM in high gear....so all is well. Refreshing the rear brake shoes and wheel cylinders is noticeable when stopping. Now.....on to the Thibeault stainless steel exhaust system install!