[zephyrracer]

My 68 GTO has had worn syncros in the 4 speed and now I have a broken ear so instead of rebuilding what I have is there a 5 speed out there yet that doesn't need tunnel mods and the shifter in the right place, I also have a console I don't want to cut up.

Thanks in advance Gregg

[tom s]

Maybe the Richmond 5 speed OD unit.Not sure about the shifter with a console.Tom

[Alanjnc]

I just put a TKO 600 in my 69 GTO. You cannot imagine how much better it drives. The only thing I sacrificed was the porch, so I just bought another one and kept my original. No one would ever know when I change the four speed back. ( in case I sell it or concourse restore it ).
I did put a new body mounts all the way around to gain as much clearance between the body and frame as I could .
I bought it from American powertrain and they shave the top of the five speed to fit. Console works perfectly. P.m. me if you have questions. 2.87 first, 4th is 1:1, 5th is .64 OD.
Crossmember just slides back two inches and the frame already had the holes drilled it from the factory.
Need to trim the transmission mount to fit into the crossmember.
Cannot tell you how worthwhile it is! 75 miles an hour in 2000 RPM. Pontiacs love that RPM range!!

Cool calculator here.
http://www.tremec.com/calculadora.php

[Roadking88]

I did the same change as Alan did, 100% satisfied. Would do it again tomorrow. American Powertrain is solid. Love the pull in first and the ride at 75MPH.

[will slow gto]

Alanjc and Roadking88, what is your rear gear ratio?

[David Jones]

I have a TKO600 in mine.
I started with a 3.55 rear and felt it was to tall and swapped to a 3.73. For my set-up, I've found the 3.73 to be pretty darn good. On flat ground (no/little load) I can use OD down to 45mph (or just below). Anything above that is golden.

[Alanjnc]

3:55. Car is totally stock other than the transmission

[Roadking88]

I have a 3.55 rear. Also as far as cutting the tunnel, I did have to cut a hole in the tunnel about 4 " behind the shifter opening. Behind means toward the rear of the car. It was easy to patch and the console covers that area. I was nervous when I was cutting but now I feel it was worth the work.

[zephyrracer]

Thanks for the responses this is good news, 75 mph at 2k I'm calling tomorrow to work out a deal, I currently have a 4.33 rear and it screams down the street , fun to drive locally but looses alot traveling sounds ,will do this to my 66 when I get that far along.

Take care Gregg

[67GTONUT]

I also want to do this in the future....

currently have 3.36 gears.....

With .64 OD it looks like I will be turning slightly less then 2000 rpms at 70mph ......

Too low?

[tom s]

The rear end gear and the OD really depends on your engine and driving habits.If your engine does not like being under 1800 RPMs in 5th gear than you will be pulling it back into 4th when your street driving at 50 MPH.With my car 3.90s is all my engine can handle on street diving in 5th gear without pull back to 4th.Tom

[zephyrracer]

One more question , is there an aliment that needs to be done and if so what's involved and how hard.

Thanks again Gregg

[400 4spd.]

Another vote for American Powertrain. Talk to Ross, he knows his stuff.
I just got a 6 speed from them for a '53 pick up we are doing.

[Scarebird]

Check the input shaft lateral play before installing:

http://www.tremec.com/anexos/TRTB0050306_131.pdf

Mine howls in 4th, Tremec tells me it's driveline angle and refuses to send a shim repair kit because the 180 day warranty is over. Were your car mine I would M22Z it with 3.08 gears out back; no tunnel, console or driveshaft mods and that lovely Rockcrusher whine in 1-3...

[Alanjnc]

Thought of you today while I was tooling around at 75 miles an hour! LOL. Yes the Tremecs have extremely little play, I think .0005 inch, so the bell housing needs to be indexed.