Tremec Transmission Conversion

 

Thanks go to Don Mueller who sent this info! Contact Don Mueller at wisdonm@yahoo.com.

 

The Heavy Duty "World Class" T-5 Tremec appeared in '85. It is rated for 330 ft-lbs. of torque. Remember, the old engines are rated at "gross" while the "new" Tremec is rated at "net". "Gross" is usually a 20-30% more than "net". The gear ratios are:

           "Italia"      "World Class"  "IM factory claimed"
          Top Loader        Tremec          Top Loader

1st         2.78             2.95              2.32
2nd         1.93             1.94              1.69
3rd         1.36             1.34              1.29
4th         1.00             1.00              1.00
5th                          0.63

The Tremec five-speed uses the Top Loader trans-to-bellhousing mounting-bolt pattern, but it's standard input shaft length is the same as an '83-'93 Ford V8 T5...about 5/8 inch longer than a small-block V8 type Top Loader. A big block Top Loader shaft is even shorter.

There are two ways to install a Tremec on a early style V8. Spacer plates are available from Dark Horse Performance, Mcleod Industries, Total Performance, and Mustangs Unlimited that let you bolt a Tremec up to a stock-type Top Loader bellhousing or equivalent aftermarket scattershield.

A better way is to use the correct-length (shorter) input shaft and required corresponding shorter bearing retainer is available from Tremec distributor Dark Horse Performance. A complete input shaft kit is available from Mustangs Unlimited. The kit contains the short input shaft, bearing, bearing race, shim kit, front bearing retainer, retainer oil seal, and retainer bolts. The kit is part # TRO132 and costs $160.

Either way, the stock clutch and clutch linkage remains unaffected.

Mustangs Unlimited also has a Tremec shift lever that has the appearance of a late sixties Top Loader. It is part #ENG670092 and costs $140.  Overall, the Tremec trans case length is about the same as the Top Loader, but the mount is slightly further back. If installing the Tremec using a bellhousing spacer plate, slide the trans-support straight back from the forward C4/four-speed holes so it lines up with the rear C6 mounting holes. New holes may have to be drilled. If installing the Tremec using the optionally available short input shaft, use the rear holes, but try turning the mounting pad around (which actually pus the mount closer to the front).

The special "short" input shaft lets the existing driveshaft and 28-spline yoke bolt up to the standard Tremec 3550 with no mods required. With the spacer, you'll need to shorten the driveshaft 5/8 inch.  Heavier-duty TKO Tremecs require a 31-spline C6-style yoke.

Sources:

Dark Horse Performance
16617 SE 134th St.
Renton, WA 98059-6923
425-227-7778
www.darkhorseperformance.com

Mustangs Unlimited
185 Adams St.
Manchester, CT 06040-1972
800-243-7278
www.mustangsunlimited.com

McLeod Industries
1600 Sierra Madre Cir.
Placentia, CA 92870-6626
714-630-3668

Total Performance
44050 N Groesbeck Hwy
Clinton Twp., MI 48036-1108
810-468-3673