warner or chevy trans id

[jocko]

gents,
how does one (easily) go about determining whether his 66 C10 has a warner or chevy 3-speed manual trans? According to the docs I've read, these were the only 2 options for a 3-speed manual that year - I know the ratios in each, just not absolutely positive WHICH one I have. What vis cues are there? Thanks.

[raycow]

The Warner T-89 has a 9 bolt side cover. The GM-built SM318 has a 4 bolt cover. If you actually do have the T-89 it is SCARCE! It is a very good transmission, but it cost the buyer nearly as much as the 4 speed, so not very many were ordered.

Ray

[jocko]

Originally Posted by raycow

The Warner T-89 has a 9 bolt side cover. The GM-built SM318 has a 4 bolt cover. If you actually do have the T-89 it is SCARCE! It is a very good transmission, but it cost the buyer nearly as much as the 4 speed, so not very many were ordered.

Ray

Excellent, thanks raycow

[jocko]

so, i think that means that i have a 3.94:1 first gear ratio (I think), which would explain why my 1st gear is only good up to about 5-10 mph before I rev to the moon...

Reason I'm researching is I'm trying to decide between TKO 5-speed options. I have a 3.73 rear - and could probably keep that if I went with the 2.87 1st gear TKO vice the 3.27 first gear ratio. Trying to only change the trans vice trans AND rearend to get what I'm looking for perf-wise and cruise-wise on hwy.

My biggest concern is that if I go from a 3.94 1st gear to a 2.87 (while maintaining 3.73 rear gears) I'll lose too much off the line perf, that's almost a 40% reduction (i.e. from a 14.7 to a 10.7 first gear cumulative ratio). Whereas the 3.27 first gear TKO only drops me to a 12.20 cumulative first gear ratio. I do want it to drop some because my current 1st gear/rearend combo is kinda ridiculous, but hard to say which is most driveable/best accel tradeoff. The advantage of the 2.87 first gear TKO is that it's final drive is .64 vice .68.

[raycow]

You might have run into a typo there. 1st gear on the most common SM318 is 2.94, not 3.94. There are other versions with about a 2.5 1st, but those were used only on cars, not trucks. The 2.87 TKO should be your best match.

Ray

[markeb01]

IMO going to a 2.87 first is going to be about ideal for a launch ratio. The early 60's performance standard was a 2.20 low gear with 4.11 axle gears which provides a 9.04 launch ratio (1st gear x rear axle) and of course considering tire diameter.

Your current 3.94 1st x 3.73 is 14.69 which is way too deep for normal driving. With the 2.87 1st and 3.73 rear the launch ratio will be 10.70, or almost exactly the same as my Super T10 4 speed. I have a 2.64 low gear with a 4.10 Dana rear end which equals 10.82. On level ground it will launch easily without throttle and no clutch chatter. Mine will easily climb to 35+ mph in 1st without tasking the engine like the low gear you currently have.

[jocko]

thanks guys - but I have to admit, after shopping around at the carlisle show - I'm actually starting to lean toward a T5. Less than half the price of a tremec and should easily handle my little 283. My goal is driveablilty, with some nostalgic engine stuff - but not 800 hp. Well, maybe.... Naaa.

Some good scores at carlisle today (sorry, forgot my camera this time...) but picked up a set of carter wcfb's for the offy manifold i've had collecting dust for ages, and finally found a pretty good set of 59 impala poverty caps. And a bagfull of other crap that i may never use, but will make good garage art.

thanks again for the help on the trans id and the ideas.
jocko