5- Speed Transmission for 1967 Corvette

[Herb E.]

I'm wondering what you folks think about using the Tremec TKO 600, PN: TCET5009 5-Speed Trans behind my Anniversary ZL1 427 Motor with 336 rear gears. Normal street driving to and from car shows, tend to hammer 1st, to 2nd, to 3rd gears occasionally. Rarely drive over 70 on Interstates or Turnpike.

[Jim T.]

Re: 5- Speed Transmission for 1967 Corvette

Your driving as mentioned is going to and from car shows, is the 5 speed really going to be a big benefit for gas mileage going to the events? Your third gear is probably good for over 110 mph with your 427 and 4th gear for say 130+?

[Joe L.]

Re: 5- Speed Transmission for 1967 Corvette

I'm wondering what you folks think about using the Tremec TKO 600, PN: TCET5009 5-Speed Trans behind my Anniversary ZL1 427 Motor with 336 rear gears. Normal street driving to and from car shows, tend to hammer 1st, to 2nd, to 3rd gears occasionally. Rarely drive over 70 on Interstates or Turnpike.

Herb------


For your kind of driving (or even more than your kind of driving), it's going to take about a hundred years to amortize the cost of the 5 speed installation with fuel savings. As far as performance goes, I don't think the benefit, if any, is worth the cost.

[Gene M.]

Re: 5- Speed Transmission for 1967 Corvette

Herb,
A 5 speed is my new choice for my '65 as we have been on road tours and 3 grand at 70 MPH is too much wear and tear. I would prefer more like 75 MPH. So I just purchased a Tremec TKO 600 for it. We do drive it a lot. Better gas consumption won't hurt neither. Next step after that is air.

[Edward J.]

Re: 5- Speed Transmission for 1967 Corvette

To add to Genes comments, If your car is a side pipe car, It will surely save your hearing, and you'll at least be able to think straight. Surely that's worth something. Lower RPM's will help quiet the cabin some and generate less heat through the floors.

[Gene M.]

Re: 5- Speed Transmission for 1967 Corvette

To add to Genes comments, If your car is a side pipe car, It will surely save your hearing, and you'll at least be able to think straight. Surely that's worth something. Lower RPM's will help quiet the cabin some and generate less heat through the floors.

Also a good add is floor insulation, it quiets as well as keeps some floor heat from going into the cabin. I got some of the thin air type w/foil and a noticeable difference. Just use care in install and the judges will not notice it.

[Chuck B.]

Re: 5- Speed Transmission for 1967 Corvette

I've put 5,000 miles on my '65 L84 coupe since installing a Tremec TKO 600 15 months ago. I didn't want to give up the 4.11 rear axle, and the overdrive 5th gear is great for lowering RPM's at interstate speeds. Improved gas mileage is also a plus.

[Philip P.]

Re: 5- Speed Transmission for 1967 Corvette

And I got criticized for using a Pertronix.

[Terry D.]

Re: 5- Speed Transmission for 1967 Corvette

What do you care what other people here think? It's your car do what you want, but most of all drive it. You'll love the five speed, have had one for 4 years now and put 3 times as many miles on my car a year than before. Be careful where you buy the five speed. Drop me a line and we can discuss this if you like.

[Tom H.]

Re: 5- Speed Transmission for 1967 Corvette

I have driven C2's since 1967, (including one with side exhaust), but never noticed a "problem" until I got my six speed '01. Now I'm always looking for 5th gear on my '66! Along with the huge steering wheel, dimmer switch on the floor, vent windows, barebones radio (advance at the time), etc, these are the great things about having a 50 year old classic for someone like me who only cruises with it!

[Herb E.]

Re: 5- Speed Transmission for 1967 Corvette

Thank you all for your helpful replies. My reasons for replacing my M-20 Wide Ratio Trans. was to get the RPM at 70-73 MPH down to about 2,000 - 2,100 RPM while cruising on the Turnpike or Interstates. I do have side pipes and after awhile, they are murder on the ears. I am 67 yrs. old and have developed Tinnitus in my left ear. The sound coming out of the pipes is "music to my ears", but the years have taken their toll. Now after awhile, it actually hurts!! Also, saving the gas allows me to travel further without stopping for fuel all too often. I mainly was wondering if the Tremec brand was a good choice as far as strength and durability. Herb

[Gene M.]

Re: 5- Speed Transmission for 1967 Corvette

Herb,
From my investigation on the Tremec brand, you should enjoy the ride. I will have more to say on it once my new ordered tranny and parts arrive and I get it in. Should be here in two weeks. TKO 500 has a vey low 3.27 1st gear. So I selected the TKO600 which has a 2.87 first gear. That will give the feeling of a 3.70 rear end starting off with my 3.36 rear end. The 0.64 over drive yields me a 2.15 over all gear for 75 mph highway use.

[Herb E.]

Re: 5- Speed Transmission for 1967 Corvette

Herb,
From my investigation on the Tremec brand, you should enjoy the ride. I will have more to say on it once my new ordered tranny and parts arrive and I get it in. Should be here in two weeks. TKO 500 has a vey low 3.27 1st gear. So I selected the TKO600 which has a 2.87 first gear. That will give the feeling of a 3.70 rear end starting off with my 3.36 rear end. The 0.64 over drive yields me a 2.15 over all gear for 75 mph highway use.

Gene, thanks for your reply. I also chose the TKO-600 for the same reason. Originally I had a M-21 close ratio Trans. With a 2:51 1st gear, which proved too high with the 3:36 rear. I changed out the cluster gear to turn this into a M-20 wide ratio Trans. with a 2:56 1st gear, which made all the difference in the world. I can't remember if I also changed the input shaft to do this or not. Anyway, I'm wondering if the 2:87 1st gear will prove to be too low, time will tell. It can't be as bad as the 3:27 1st though. Don't want to end up with a "stump puller". Let me know how your's works out. I won't have mine running for another month or two.

[James W.]

Re: 5- Speed Transmission for 1967 Corvette

Herb,

In the recent NCRS Road Tour to Hampton Roads I ran with the Rocky Mountain Chapter from Tulsa, Oklahoma and back to my home state of Nebraska. There was a gentleman that drove his 1967 Corvette 427/400 equipped with a 5-speed gearbox and he had no problems at all keeping up with all the late model cars. I have to hand it to him and one other couple that drove their L84 equipped 1963 which was flight judged round trip with very few problems. I used to do that before I bought a late model. You really get spoiled and it's hard to go back to driving the older cars long distance. Keep us posted on the install.

Regards,

James West

Gene, thanks for your reply. I also chose the TKO-600 for the same reason. Originally I had a M-21 close ratio Trans. With a 2:51 1st gear, which proved too high with the 3:36 rear. I changed out the cluster gear to turn this into a M-20 wide ratio Trans. with a 2:56 1st gear, which made all the difference in the world. I can't remember if I also changed the input shaft to do this or not. Anyway, I'm wondering if the 2:87 1st gear will prove to be too low, time will tell. It can't be as bad as the 3:27 1st though. Don't want to end up with a "stump puller". Let me know how your's works out. I won't have mine running for another month or two.

[Jim H.]

Re: 5- Speed Transmission for 1967 Corvette

I ran an M20 in my '66 SB coupe w/sidepipes for about 3 months and got tired of hugging the slow lane and staring at my temp gauge in the So Cal summer heat, so I converted to a Tremec 5-speed (the TK 600, IIRC). It simply transformed the car! There was no compromise at low speed and the ability to run at 170 degrees temp at 2000 rpm at LA highway speeds w/all the BMW, Lexus, Merc luxo cruisers was major from a driveability, safety, and fatigue perspective. The biggest problem with the 1:1 4 speed at highway speed is everything gets very busy w/the engine turning 3200-3400 rpm and the effect is exhausting after a 2-3 hour drive - even with ear plugs to drown out the pipes. I found the Tremec shifts to be crisp and certain and unless you get under the car (or install the supplied 5 speed console placard) no one knows you're running it until you blow by them.