T-90 vs. T-14

My '70 CJ has a stock :v6: mated to a T-90J, and a Warn OD, with 4.88 gears.
While reading through the recent "5.38 vs. 4.89" thread (are they 4.88 or 4.89 ?) I was interested in this info posted by oldtime-

T90A (2.79 x 5.38 = 15.0/1 Take Off Ratio.
T90A (2.79 x 4.89 = 13.7/1 Take Off Ratio
T90C (3.339) x 5.38 = 17.9/1 Take Off Ratio
T90C (3.339) x 4.89 = 16.3/1 Take Off Ratio
T14 (3.14) x 5.38 = 16.9/1 Take Off Ratio
T14 (3.14) x 4.89 = 15.4/1 Take Off Ratio
T15 (2.99) x 5.38 = 16.1/1 Take Off Ratio
T15 (2.99) x 4.89 = 16.1/1 Take Off Ratio
T98 (3.09) x 5.38 = 16.6/1 Take Off Ratio
T98 (3.09) x 4.89 = 15.1/1 Take Off Ratio

My dad still has the stock T-14 that was in my Jeep. My thought is that I'd really like the 3.14 1st gear of the T-14 vs. the 2.79 I have now.
The obvious problem would be coming up with a 10 spline OD instead of the 6 spline that I have now. My other concern is, I know the T-14
does not have a sterling reputation for durability. Am I really giving up anything, strength wise, by going to the T-14 instead of the T-90?

 

D-44 uses 4.89 ratio
D-25, D-27 and D-30 use 4.88 ratio

4.89 = 44 ring count 9 pinion count
4.88 = 39 ring count 8 pinion count

If memory is working correctly today the T-14 is 3.10 first gear ratio and not 3.14.
I just now corrected that post.
T14 (3.10) x 5.38 = 16.6/1 Take Off Ratio
T14 (3.10) x 4.89 = 15.2/1 Take Off Ratio

I'll suggest installing a Borg Warner T-15
It uses the 6 spline mainshaft and bolts direct to the D-18/20 Texas pattern.
It's 10" OAL plus a 1-5/8" thick GM bellhousing adapter.
It's 1st gear ratio is 2.99/1

T15 (2.99) x 5.38 = 16.1/1 Take Off Ratio
T15 (2.99) x 4.89 = 14.6/1 Take Off Ratio

 

The biggest issue here is cost. I'm on a limited budget. I already have access to a good T-14. I'd have to find & purchase a good T-15.
Hopefully I could either trade overdrives with someone, or just sell mine & purchase the correct one.
Again, little or no cost.

 

So the T-14 has a rep for being weak, but compared to what? I don't think it is compared to the T-90. The gear size isn't that different. The T-90 has straight-cut 1st and reverse, which is stronger than bevel cut, so there's that. I've heard of breaking the T-14 when it's put behind a 360 in an intermediate CJ. I've heard of breaking 2nd gear on a power upshift. In terms of strength, I don't think it's a downgrade from the T-90, and it should be an upgrade since it's newer and fully synchromesh. I'd say the T-14 in good condition will be fine for the 225, 232 and 258, as long as it is not abused.

 

Yeah Doug I understand.
I was just thinking it might be another possability if you happen across a cheap T-15.
Check out CL for your area. T-15's show up ever aso often.
If you can do an even trade O.D. swap then the original Borg Warner T-14 also makes good sense.
Besides....re-installing the T-14 just might improve the retail value of your jeep a little.

 

I have the original 1970, T14A, 4.88 D44 flanged (4.89?), 225 V6 and have never had an issue with the transmission.
Way back when, I broke the front diff trying to get unstuck and up a steep hill in deep snow. the diff was well work due to not much oil in there.
The T14A may be the weakest transmission that you can shoehorn in to a cj5, but that does not make it weak.
What is your use? Doing some racing with a built motor? might be an issue
Sunday drives on pavement or some tough off road stuff handled with care and caution? no problem

There are no cheep conversions, in my opinion.
Herm the OD guy might have used bowl gear for the 10 spline.
Mine has an adapter on the front to mate with the Buick bell housing, do not know about the 4 banger.
Cross member mounting will be next.
If the overall length is different then the drive shafts must be considered.