Conversion to Keisler 5-Speed

[Joe R.]

Re: Conversion to Keisler 5-Speed

Hi Peter:

I am in the middle of installing a Keisler 5-speed in my 67 300 HP right now. I understand your concerns about affecting the value of the car, but this is a bolt-in swap that is easily reversed. If you keep your old transmission you can put it back in any time you want, in one weekend.

I thought about this swap for a long time. After taking my car through the NCRS judging process and achieving Top Flights at the chapter, regional, and national levels, I thought it was time to make some bolt-in improvements that would make the car more fun to drive. My only rule is that any changes I make must be bolt-in only and completely reversible.

For a small block with a 3:36 rear, I would recommend getting the TKO 600 "close ratio" version with the optional 0.82 5th gear. I think the .68 5th gear is a bit too tall for a 327. The 2.87 first gear of the TKO 600 is more than enough for improving your first gear launch, compared to the 2.20 of a Muncie close ratio or the 2.56 of a Muncie wide ratio.

Regarding the fitment issues getting the Tremec into a 67, I have only one small area where a downward protrusion on the top of the tunnel (where the center dash panel is riveted to the tunnel) just touches the transmission. I'm still working on that issue but I have several options that do not require cutting the fiberglass.

Once installed, the Tremec actually has lots of clearance on the sides and almost all of the top. The main problem is that it is *very* difficult to get the transmission into place. You need a good transmission jack and you have to follow a very unusual installation sequence that involves getting the bellhousing in place before the clutch is installed. Everything goes in, but just barely.

I'm not finished with my swap so I can't comment on how my car drives, but last year I drove a friend's 66 300 HP with the Tremec and I really liked it.

[Lorne G.]

Re: Conversion to Keisler 5-Speed

Sorry for the time lasp in replying but I agree totally with Joe. I just bought the TKO600 for my 67 big block and look forward to putting on many happy miles and smiles. I too have a slight clearance issue which I brought upon myself by not removing the tunnel insulation as instructed.

I installed the same tranny in my 67 Nova a couple of years ago and really enjoy the added performance and fuel economy on long distance runs.

In the end, it's whatever makes you happy and want to drive your car more.

Lorne

[John C.]

Re: Conversion to Keisler 5-Speed

Peter,
I go along with Joe. I've done two so far with the TKO 600 and I changed the rears to 370, best thing since slice bread, you can always put it back to stock. What I did to give me a little more clearance on the top of the transmission I put two round rubber body mounts with a couple of shims on top of the cross member .
JOHN

[Lorne G.]

Re: Conversion to Keisler 5-Speed

John, before you put the rubber bushings on the crossmember did you have issues with the tranny touching the floor anywhere? I am getting a slight rattling sound but not a vibration. I left the tunnel insulation in and I know I must remove it but with the tunnel insulation in place I can not see if the tranny is touchinfg the floor although it is wedged into the tunnel insulation and crushed it.

Lorne

[Joe R.]

Re: Conversion to Keisler 5-Speed

John, before you put the rubber bushings on the crossmember did you have issues with the tranny touching the floor anywhere? I am getting a slight rattling sound but not a vibration. I left the tunnel insulation in and I know I must remove it but with the tunnel insulation in place I can not see if the tranny is touchinfg the floor although it is wedged into the tunnel insulation and crushed it.

Lorne

Hi Lorne:

I took the tunnel insulation out because Keisler said to, but after completing the installation I found that it probably could have been retained if I simply made a larger cutout in the top of the insulation. The Tremec actually has very good clearance on the sides, but there is one small point of interference on the top of the transmission. The attached photo show this location.

The Keisler-supplied 5/8 inch spacers for the center crossmember help a lot, but my car needed just a tad more space. As you can see in the photos, I tried some gentle clearancing of the fiberglass protrusion in the tunnel, and some clearancing of the transmission cover lip. This was still not quite enough.

In the end I modified the Keisler transmission mount to drop it about 3/8 inch, as shown in the attached photo. This provided more than enough room. I then used shims between the rubber transmission mount and the Keisler mount to raise the transmission until I had 1/8 inch clearance in the tunnel.

By the way, I now have about 250 miles on the Tremec and I absolutely love it.

[Lorne G.]

Re: Conversion to Keisler 5-Speed

Thanks for the photos Joe. They help alot. I may try to work around the tunnel insulation if possible but I need to find out where the tranny is touching the floor first.
I am using the Classic Chevy 5 speed version from California and their mounting bracket may be a little different than Keislers. I tried lowering the tranny but it hits the crossover so i guess from this lowest point I need to raise it just enough that it does not hit. I was worried about the pinion angle and vibration if i had the tranny too low. Do you think thast is a concern?

Lorne

[Mark W.]

Re: Conversion to Keisler 5-Speed

I had the Keisler TKO 500 installed in my '66 L79 with 3.70 gears in March '08 and have put about 2000 miles on it. I absolutely love it! It is so much fun to drive whether you're smokin the tires in 1st or crusing at 75 mph in 5th. I agree with others that the swap doesn't require any modifications and can easily be changed back to the original trans. The recommendations to put in new body mounts or shims is spot on and Keisler recommended that to me as did the shop that did the install for me. Driving the car only 500 miles per year would be the big question mark for me as this is not an inexpensive proposition.

[Henry A.]

Re: Conversion to Keisler 5-Speed

There is a potential for a vibration. You will know when you drive it. I had one that took quite awhile to figure out and fix. Let us know how it drives out.

[Joe R.]

Re: Conversion to Keisler 5-Speed

Thanks for the photos Joe. They help alot. I may try to work around the tunnel insulation if possible but I need to find out where the tranny is touching the floor first.
I am using the Classic Chevy 5 speed version from California and their mounting bracket may be a little different than Keislers. I tried lowering the tranny but it hits the crossover so i guess from this lowest point I need to raise it just enough that it does not hit. I was worried about the pinion angle and vibration if i had the tranny too low. Do you think thast is a concern?

Lorne

Hi Lorne:

If you still have tunnel interference when you lower the Tremec until the tail housing rests on the crossmember, something is very different from what I had with my car. Have you already installed 5/8 spacers between the crossmember and the floor pan? These help the clearance considerably.

Keisler says that the floor pan can sag over time, but I don't know if that is really the case. However, the floor pan is completely unsupported except at the outer frame rails, so there is a lot of flex in the center, especially with passengers sitting in the seats.

I found that my floor pan would readily lift the necessary amount to insert the Keisler 5/8 inch spacers. When it turne out that this was not quite enough, I considered pushing the floor up further with thicker spacers, but I didn't want to put too much stress on the floor pan. So, after installing the 5/8 inch spacers, I modified the rear mount to get the additional clearance I needed.

Regarding the drive shaft angle and possible vibrations, I am aware that this is a concern. I believe the goal is to keep the tail housing as high as possible. If you get vibration with the tail housing as high as possible, you need to either lift the body at the body mounts, or push the differential pinion down with a spacer of some sort.

I decided to start by placing my transmission as high as I could while leaving 1/8 inch tunnel clearance, and then see if I had a vibration problem that required further steps.

So far I have only taken the car up to about 70 MPH, and I do not detect any unusual vibrations. However, I see that the universal joints are "spraying" grease out of their seals onto the floor boards, which seems odd to me. I wonder if there could be a vibration that I don't feel that is causing this, or whether this is just normal for new U-joints. I'm watching the situation to see if it continues.

[Joe R.]

Re: Conversion to Keisler 5-Speed

There is a potential for a vibration. You will know when you drive it. I had one that took quite awhile to figure out and fix. Let us know how it drives out.

Hi Henry:

Can you describe the characteristics of the vibration that you had?

For example, did it show up in the shifter or come through the floor? Did it have a specific speed range that you could "drive through," such as 40 to 50 MPH, or was it fairly constant? At what speed did it set in?

I don't notice any specific problem with my car so far, but I have read that some people have vibration problems. I'm trying to determine what I should be on the lookout for.

[Lorne G.]

Re: Conversion to Keisler 5-Speed

Hi Joe,
Thank you for your well detailed clearance fix. I am just at the point now of trying to locate where the tranny is hitting the floor to determine how much I need to drop the tranny, lift the floor, or do a combination of both.

Currently the tranny is bolted in using a spacer of about 3/16". When I removed the spacer the tranny was almost hitting the crossmember but i could not determine if the tranny was still hitting the floor as I could not see past the insulation.

My next move is to remove the insulation for better sight of the tunnel, lower the tranny about 1/8", and also raise the floor using 5/8' rubber spacers as you did. I am hoping this combination will fix my problem.

I will let you know the outcome.

Lorne

[Duke W.]

Re: Conversion to Keisler 5-Speed

Dear Patrick,

I put about 500 miles a year on the car, it has a 3.36 rear end. I'm looking for better acceleration off the line and lower rpm's at cruising. Maybe what I should be looking for is an already modified driver.

Peter

If you have an original '67 L-79 drivetrain with a 3.36 axle then the trans is the WR version - 2.54:1 first gear. This yields about the same overall 1-3 multiplication as a CR trans (2.20 first) and 3.70 axle. Either should allow you to light the tires from a dead stop if that's your thing.

You can buy a ten buck spring kit and quicken the centrifugal spark advance curve to the limit of detonation, which will improve the low end torque. This is a lot cheaper than changing the transmission for lower gearing for the same effect.

For the amount you drive and considering what the conversion will cost and the loss of originality, I think you are throwing money away.

The WR trans with a 3.36 axle is a pretty good overall combination - not the best for drag racing, but reasonable off the line performance and about 2600 revs at 60, so it's a decent cruise gear unless you do long trips all the time.

If you do go ahead with the conversion, get the ratio set that Joe Randolph bought.

Duke

[Joe R.]

Re: Conversion to Keisler 5-Speed

Hi Lorne:

You might try installing the 5/8 inch spacers first, to see it that cures the problem. That way you get to leave the insulation in place.

If you do remove the insulation, you will find that there is plenty of room on the sides of the transmission and over most of the top. The interference is only over a portion of the stamped sheet metal cover that is silver in color.

BTW, with the insulation removed, an easy way to check clearance is to use a thin piece of cardboard, such as the backing from an 8.5x11 inch pad of paper. From the driver's side, insert the cardboard up and over the top of the transmission, between the transmission and the tunnel, to see if there is clearance for it to slide all the way over to the passenger side.

[Lorne G.]

Re: Conversion to Keisler 5-Speed

Thanks Joe ,
I will follow your recommendations and post my results.

Lorne