Starfury

Yes, you can. The only thing you'd need to do is remove the under-dash clutch assist spring. Diaphragm clutches require much less pedal effort than long-style clutches, so the assist spring is generally not needed. If you leave it in, it tends to cause the pedal to stick to the floor during high rpm shifts. This is especially prevalent with clutches withcentrifugal weights.

dcohen

yes, you can

my 66 had a diaphragm pp with a 3 speed toploader, i went back to a long style zoom pp

but then again, my 289 will be lucky to see 350hp

urban_cowboy

That is really good to know. The 5.0 mustang guys have caused there to be SO many more options for diaphragm PP. If my 2400lber does not hold up, I will head in the Centerforce centrifugal PP direction. I just have not been able to get any info on what was needed to make the switch. Thanks guys.

urban_cowboy

David Kee called today and my toploader is done. I ran by his shop today and decided to have him order me 1350 U joint yokes front and rear. I am tired of stuff dieing! Nice guys over there. David thinks this tranny will hold together for me, but said the next upgrade is to switch input shafts over to a big block setup, which means changing forks, clutch, and pressure plate, so we put that one off for a while.

While I was there I chatted with him about his race toy. A 1969 Falcon, which I mistakenly thought was a Fairlane, with two stages of nitrous. It is a small block running mid 7s, I think he said. He said it spun the tires on the dyno with one stage and measured it out at 1000hp without the second stage. That made me feel better that he understands what I need.

If you guys are in needed of a new toploader, he seams like a great guy and was pretty fast. He told me three weeks, and it was 10 days. The yokes will not be in until Friday, so I will know more about how the tranny holds up next week.

His shop is in San Antonio, TX and his web address is http://www.4speedtoploaders.com/

67mustang302

Toploaders are good transmissions. I just swapped a TKO 600 into mine, replacing my Toploader. Gonna rebuild it and keep it as an emergency backup. So, to answer some questions...

Yes, you can run a diaphragm plate on a Toploader, the Centerforces are diaphragm style.

Swapping to a TKO 600 requires a bit of work. The TKO really is a beefed up Toploader with an overdrive and an aluminum housing(and about 40 years of technological advancement).

They get harder to shift at higher rpm, but shouldn't be any worse than a Toploader. It's because they both use spring loaded detents to move a bronze blocker ring. TREMEC advises against shifting over 6,500rpm. They can be modified to shift like glass at high rpm, but usually become unstreetable as a result. Other trans like the T5's use a carbon faced synchro ring so they do better at higher rpm. I think all the T56's use carbon cone clutches in the synchro mechanisms.

The swap requires a new bellhousing, a 31s yoke, and a 26s clutch(The TKO 500 can be had with the 1.0625 10s, but then the input shaft is the weak link). I went with the Quicktime SFI bellhousing. It comes with a bunch of parts to set up different clutch forks. I imagine you could just use an early style clutch with the longer throw that has a 26s hub. I'm sure Centerforce makes one. Otherwise you can go to a late model clutch setup like I have, which requires either hydraulic or cable. There are plenty of hydraulic and cable kits out there for our cars. I'm running a McLeod hydraulic setup on mine, and since the TKO and Toploader share MANY of the same design specs, I literally pulled the t/o bearing/slave off the Toploader bearing retainer sleeve and slid it onto the TKO. Reset the clutch adjustment(different length input shafts) and it was good to go.

The driveline length will need to be checked, most setups require a shorter driveline, but it really needs to just be measured. The TKOs come with a Hurst billet aluminum shifter and the trans has built-in internal stops, so all you need is a stick and a ball. Most Hurst sticks fit. Again, the stick from my Toploader shifter bolts right up.(noticing a pattern here?) The shifter also comes out of the trans tunnel in the stock location, or at least it did on my 67.

You also need a crossmember, which you could fab yourself, I got mine from Modern Driveline. It's a nice unit, heavy duty and bolts in very nicely. It's designed to sit the trans a bit lower so it fits easily in the tunnel, so it tips the back of the trans downward, make sure to check output pinion angle. I had to shim the trans up a tad, but will prolly end up going to adjustable engine mounts to set the engine lower rather than shoving the trans up in the tunnel.

You also need a different speedo gear. A shorter cable is nice since the mech speedo input on the TKO is on the driver side, as opposed to the Toploader's passenger side. You need a TKO/T5 speedo gear, since the spline is cut with a twist in the opposite direction.

You prolly don't want a Jerico for a street car. They are awesome transmissions, but the dog ring and slider is not optimal for regular driving. A lot of clacking and clunking as you put it in gear. Besides, if you have a street car with so much power that a TKO can't handle it, then it's not really a street car. Jericos are also freaking EXPENSIVE!!! I mean like $4,000+ for a 4 speed and $5,500+ for a 5 speed.

Anyway, basically the TKO 600 is a 1 1/8" 26 spline input, 31 spline output, aluminum case 5 speed beefed up Toploader.