Thinking about making the swap.

Anyone have any experience with the American Powertrain: Tremec 5 speed or have recommendations for something else?

 

Silver Sport Transmission also sells the Tremec TKX 5-speed.

https://www.shiftsst.com/

There are lots of YouTube videos on the install.

 

I got my Tremec from American Powertrain. I bought the kit, which included mounts, shims and driveshaft. They also included a CD with installation instructions including how to shim the bell housing if necessary. No problems or issues. That was about 15 years ago. Jerry

 

What rear end ratio do you have? 5th gear is an overdrive so a numerically low ratio - e.g. 3:08. - is not ideal.

 

There isnt any really good option other than the TKX for a modern feeling overdrive tranny in a Vette.
I made my own kit and am very satisfied buying the TKX from Summit and the Modern Driveline Shifter through Performance Parts Warehouse. I had the driveshaft made locally.

I went with Summit using their Credit Card through Synchrony which gave me 0% interest if paid off in 18 months I believe. If you go this route you need to pay over $100 more than the monthly minimum or you will get killed by the interest charge. Also I use their Summit bucks membership which gives me credit for spending at their sight and I used a coupon that saved me an additional $120 bucks plus free shipping. I had already had a removable crossmember and went with a required a $205 31 spline1350 front slip yoke https://www.moderndriveline.com/shop...emovable-caps/ for the 500 ftlbs/ 500 hp for my 427 which required some transmission tunnel fiberglass work. This also required a new custom driveshaft which was about $329 at Gilberts in NH.
I may have not saved much in the end but I am satisfied with my route.


Heres some helpful things you may need to consider while making the decision.


There is a few options for first gear and OD for a Chevy model TKX, which is what you want. As 69L88 stated you will have to match it to the rearend you have. Depending what you have, I would want a rear end final first gear total ratio as close to 10:1 as you can get and the Overdrive final gear ratio around 2.5 - 3:1 if its possible. you need your rear gear ratio which you can figure out by rotating the rear wheel and counting the revolutions of the drive shaft for one full revolution. Then multiply that buy the first gear choice of either 3.27 or 2.87 for your total first gear ratio for off the line performance.

Then the rear gear ratio by .68, .72 or .81 depending on which combination you select. not all combinations are available. This will be the total OD ratio. Then plug that into a transmission ratio rpm calculator https://spicerparts.com/calculators/...rpm-calculator which will give you rpm and speed using your rear tire diameter which is about 27 inches for a stock corvette size tire. This will tell you what your highway cruising will be like. Im around 2700 at 70 and just under 3000 at 80 with a 4.11 rear gear and 28 inch tires which is pretty good for what I do with my car....I drive it like I stole it.... A 3.08 would work fine with either the .72 or .81 to get the engine revs down to 2000 rpm at 65 mph which is still in most cams power curves

I use a McLeod Pro Street clutch and a McLeod Hydraulic throw out bearing that bolts in place of the front bearing retainer. You can still use your Z Bar mechanical clutch so you can save money there. If You are already using a Mcleod clutch all you need to do is buy the correct spline clutch disc, resurface your flywheel and pressure plate and install. If your pressure plate and clutch plate are not grooved or scored you can resurface them with 120 grit paper glued to a sanding block and use a circular motion to go around each plates surface to clean off the old material from the clutch disc. then follow the break in procedure from McLeod for their clutches. Basically about 500 miles of backroads driving so there is multiple shifts without any burnouts to season the surfaces.

The biggest challenge after paying for it is cutting out the transmission cross member and mounting a removable one. When you install it you will want to mount the rear of the tranny as high as possible to get the driveline angles correct which may require tilting the differential as well. I had a really thick snubber and had to install a thinner one to correct the angle so it wouldnt wobble.

 

This is great information, appreciate it.

 

Edit, I forgot to mention the dialing in of the bellhousing which is a must to prevent unnecessary wear and poor shift feeling. The old bellhousings didnt need dialing in for the Muncies or the Richmonds due to the ball bearings in the input shaft versus the needle bearings in the 5 speeds. Much more room for error in the old 4 speeds. Definitely look that up on youtube for how to do it and the bellhousing dowel pins necessary if its off which it probably is. What it is, is using offset dowel pins to move the hole for the transmission to be almost perfectly centered around the crankshaft and transmission pilot bearing in it. to the tune of .002 to .004 at the most. Its not hard but is time consuming. Depending on your attitude and if you like puzzles it can be enjoyable. I like doing stuff like that but other dont, end up going crazy, howl at the moon and vote democrat in the end...its very sad.

 

Agree with @Rescue Rogers , save for the political comment. We need to keep politics out of this.

 

 

I agree with Bikespace. Got my TKX kit through SST. Fantastic tranny and kit and the customer service is the best.