[moto-d]

Just picked up a 67 GTO 4-speed, and looking to replace the Chevy 12-bolt with 4.56s in their now, with the correct Series 3/3.55 rearend. Posi or open, makes no difference. Let me know what you've got, will travel for the right one. Thanks!

[396ss]

Still looking? I have a 70 355 posi.
Thanks,
Adam

[TedRamAirII]

It would be cheaper just to replace the gear set, then you still have the 12 bolt positraction.

[moto-d]

True, but want to return to a stock 10 bolt housing. I've got one, just need to put in the carrier and gear set. Thanks!

[moto-d]

Thanks Adam, but 70 axle housing is a bit too long for 67 A bodies.

['ol Pinion head]

Originally Posted by moto-d

Thanks Adam, but 70 axle housing is a bit too long for 67 A bodies.

Chevrolet A body rears were the only ones that followed that scenario. The '67 nodular iron 3.55 Safe-T-Track A body rear only differs from the '70 model counterpart in center housing casting number & the provision that the '70-72 Pontiac 8.2 A body rear utilizes tapered bearing axles, which by design are far superior to the previous sealed ball bearing design.

[Texas67sedan]

I have a 3.55 open rear that has fresh bearings for $450. I'm in Texas

Sent from my SAMSUNG-SM-G891A using Tapatalk

[Mrpontiac1013]

Have u found a rearend

[360Rocket]

Originally Posted by 396ss

Still looking? I have a 70 355 posi.
Thanks,
Adam

A 12 bolt? I just need a 3 series posi chunk and 3:55 gears.

[moto-d]

Originally Posted by Mrpontiac1013

Have u found a rearend

Yep, picked it up last weekend. Thanks anyway.

[Carmine]

In my '67, I ran a 3.36, 3.55 and 3.73 rear. By far, the 3.55 was the best choice for my application; stock 400 engine with 4 speed. Good choice for the 3.55, Carmine.

[moto-d]

Originally Posted by Carmine

In my '67, I ran a 3.36, 3.55 and 3.73 rear. By far, the 3.55 was the best choice for my application; stock 400 engine with 4 speed. Good choice for the 3.55, Carmine.

I've got two other '67s besides this one ... an air conditioned automatic hardtop with a 3,23 open, and an automatic-on-the-column hardtop with a 3.36 posi, They're both OK performers, but I'm looking forward to see what that 3,55 can do in the 4-speed. According to PHS, that's what the car came with, so I wanted it as stock as possible. I'm nuts for stock, lol.

[Carmine]

Should have mentioned, that one of the owners before me, had a 2.56 rear in my '67. No baloney, I could wind that thing out close to 50 mph in first gear. Why they ever did that, I don't know. I tried the 3.55 first. Thought I died and went to Heaven. Car performed great. Should have left it alone, but went to a '70 GTO rear 3.73 12 bolt posi. Ran it at the drags and the best time was a 14.2. The drags aren't everything and I didn't like the high rpm's just cruising along. Tried the 3.36, another nice ratio, but the 3.55's were the best. My son who I gave the car to, is running I believe 3.42 gears. My '62 409 4 speed came with a 3.70 posi. A lot of low end power, but high rpm's just for cruising. Didn't like them at all. Tried a 3.36 ratio which was perfect for me. On a roll in 1st gear, I can nail it and break the tires loose. Grab some rubber in 2nd. Cruise at 50 mph taching about 2200 rpm's. Engine runs all day in the heat at 180 degrees. Works for me. I do have a set of 3.55's for the car and everyone once in a while, I get the urge to swap them out. But I return to my common sense and it doesn't happen, Carmine.