T5 in my 68 GT350

[dbegley]

Question for you guys. My new 2017 GT 6 speed has me spoiled when it comes to RPM at highway speed. Some of the members of my local SAAC club tell me they have swapped out their TopLoaders with a T5. I have been doing some reading which makes me ask some questions. I know there are different models of the T5 and I would want to use the Z series. Have those of you that have made this swap had any issues with that transmission? I just street drive my GT350. Dyno'd at 260 HP at the rear wheels. Might bump that up eventually.
The other question I have is about that first gear in the T5. My car has a 3.89 rear. There is a big difference in the 1st gear in my TopLoader compared to the T5. Does that make first pretty worthless? Can I swap out to a higher 1st gear? Has anyone done that? Can you do that? Is there a smaller ratio gear available? The close ratio Toploader comes with a 2.32 gear. The T5 gear is 2.95.
The last question concerns the different pieces needed for this swap. CJ Pony offers a pretty broad kit that seems to cover all that is needed including a shorter drive shaft. Is that the way to go? Anyone know which T5 CJ offers?
thanks
Dennis

[shelbydoug]

I'm pretty sure that you need to use 1/4" spacer between the original bell and the transmission or change to the bell that matches the trannie.

The input shaft on the t5 is longer then the toploaders.

You don't need that much rear gear with the t5 2.95 first gear. A 3.00:1 rear will give you the same ratio but a 3.50 will give you great 0-60 times.

I went with a Richmond 5speed for the torque handling abilities and use a 3.50 rear with the 3.26 first gear.

It's all a matter of choice of what you want to do with the rpms and where to put 'em.

[KR Convertible]

I think first gear is going to pretty short with a 3.89.  I have a 3.00 and it seems a little short.  Call Modern Driveline, maybe there are different ratios available.  There is a low profile TKO trans that will handle more torque.

If you go with a T5, you can add a spacer (about 5/8") between your factory bell and the trans and use the factory Z-bar.  The other option is buy a Tremec bell and use either a clutch cable or hydraulic.  I have a spare Tremec bell and clutch cable set up if you're interested.

The Richmond trans, from what I recall, doesn't have overdrive.  It's a five speed with 1:1 final ratio.  They might make an overdrive one.

[zray]

Yes, with your current rear gearing , first bear is worthless. So essentially, you are back to a 4 speed. A weak 4 speed at that. All it takes one fast shift and the T-5, any T-5, is in danger of sheeling teeth like corn on the cob at a county fair.

If you can't stand the higher rpm, why not buy a 3.25:1 or 3.50:1 pumpkin already assembled. It will take about 2 hours to make the swap.

If you ever sell the car it's easy to reverse the modification.

Z

[pmustang]

I have a T5z in my 66 350 with 389s

LOVE IT!

I have a T5z in my 67 clone with 3.55s, LOVE IT

I have had about 10 cars brought in for stock with them,  best mod in my opinion along with disks for a great drive

[shelbydoug]

The Richmond trans, from what I recall, doesn't have overdrive.  It's a five speed with 1:1 final ratio.  They might make an overdrive one.

Fifth gear in a Richmond 5 speed is 1:1. There is a six speed where 6th is an overdrive.

The Richmond (Doug Nash) will take the power of a big block. The T5 will not.

The T5 will take the power of a "stock 302" but that's about it, or even a stock 351.

They first appeared in the early '80s as an alternative for the 302 Mustang GT which was at best a 250hp, 325 lb-ft torque engine.



IMHO, the best solution is to consider using a 3.00, 3.25, or even a 3.50 rear  with a transmission that can take 500+ hp and spirited driving.

That means "re-aligning" the gearing which includes a rear gear change.

Generally speaking "overdrive" transmissions can not take the power for long. That's really where the concept of the Richmond gearing comes in. No overdrive in 5th.



There are other versions of the T5 like the TKO that are as hefty as the Richmond but the gear spacing varies. The Richmond's were based upon the GM T10 close ratio spacing. Others are not and have less then ideal rpm drops between gears.



Since we are talking about '68 GT350's, -02148 has the Richmond 5speed with a 3.50 rear as well as mine. Both are 500hp, 450lb-ft torque "small block" engines. First gear is 3.26.

For strictly a "cruiser" you can drop the rear to 3.00:1 and that will give you the effect of a 3.89 rear with a top loader and an overdrive.



At this point I should also mention that an "early solution" to this "issue" was the "Hone Overdrive" which if you look, was listed in the "Shelby Parts" catalog.

[pbf777]

     This is a quite common swap, installing the T-5 transmission replacing the Top-loader unit, and once complete we have never had anyone wanting to go back.   

     The T-5 to use is the M-7003-Z from Ford Racing, as this is a non stock unit with greater torque load carrying capacity vs the production units; many a sub 12 second FOX mustang exists running one. And the 2.95 first gearing will work fine with your 3.89 rear gear; remember the wide ratio Top-Loader is 2.78, not so different, particularly if one chooses to install a more aggressive camshaft & induction, and perhaps a greater than stock tire size.

     Don't mess with bell housing to transmission spacers, just use the correct T-5 bell housing unit, M-6392-E, from Ford Racing, along with the M-7007-B separator/ index plate.
     
     If you wish to retain the mechanical "Z"- bar clutch linkage, we will weld a mounting block inside the bell housing to receive the fork mounting, not complicated. But this may be the time to remedy the shortcomings of this engineering, and consider either a cable conversion or a hydraulic system conversion. We've done both, and each has it's attributes, but again, don't be under the impression that all of the "stuff" received in the "kit" will prove ideal, as often we will toss much of it, for our own fabrication.

     As such is the case with the "store bought" cross-members supporting the transmission. We generally find reworking/modifying the Ford original unit makes for a more acceptable installation.   

     Measure and have made locally a proper driveshaft, as this isn't rocket science, but does need to be done correctly. Don't assume that because it comes in a box, from the "experts", it'll be right, to many variables in the construction and component selection of the vehicle as a hole for there to be a "one-size-fits-all" solution.

     So...... no! I don't recommend buying a "kit", "with everything you'll need", as in my experience, such will not be the case! Be willing to do some fabrication work on your own, or find a capable shop to do this conversion, otherwise it will be somewhat cobbled together, with less than ideal results.  (we're in Orlando, FL.)   

     Unfortunately, generally in order to maintain proper engine and drive line alignment, some reworking or modification to the trans-tunnel if only for the shifter mechanism may be required. Perhaps, not acceptable on ones' million dollar, Shelby?   

     Scott.

     

[KR Convertible]

Below is a picture of the T5Z shifter in my 65 convertible.  No hacking required.

[dbegley]

Thanks Guys for the conversation. Lots of good info. I see that I am on point with the questions I was asking.
I will keep you posted as to my progress.