Tko 600

diegokid · #1 (**permalink**) 12-19-2010, 07:56 AM

I have a TKO 600 with the .82 OD. I regret this and wish I had gotten the .64 for highway speeds with a 3.42 rear. I did find out the gears are avaible to do the swap. Has anyone else made this change before?

mikeforte · #2 (**permalink**) 12-19-2010, 09:15 AM

Hi Diego,
I have a customer with a few sets of .64 5th gear sets for sale. These are brand new gear sets he has changed out. I'll get a price tomorrow.
Where do you live?

SPF1061 · #3 (**permalink**) 12-19-2010, 10:53 AM

What kind of rpm are you turning at highway speeds with that gear combo? The .64 will definitely drop your top gear rpms, but be aware that it is a true overdrive gear. You will really feel the rpm drop and power loss when you shift from 4th to 5th. It may be a just what you are looking for, but be aware that it will definitely turn your 5 speed transmission into a 4 speed with overdrive.

jdean · #4 (**permalink**) 12-19-2010, 02:55 PM

What SPF said. I have the .64 and it makes for a 4 speed with overdrive meaning 5th suitable only for high speed highway cruising. But that is what I planned for. On the positive side it quitens things down and improves mileage on long drives. Be sure your cam can cooperate with low RPMs without bucking or you will wish for the .82 again. Mine needs 2,000 RPM to stay smooth which means around 75 MPH or forget 5th.

decooney · #5 (**permalink**) 12-19-2010, 03:01 PM

Quote:

Originally Posted by diegokid

I have a TKO 600 with the .82 OD. I regret this and wish I had gotten the .64 for highway speeds with a 3.42 rear. I did find out the gears are avaible to do the swap. Has anyone else made this change before?

diegokid,

Check this out. I just left a breakfast meetup and one of the guys in our NorCal Cobra group has a .64 TKO 600 and wants a .82 TKO 600 and were just talking about a doing a gear swap on it. Maybe you guys can swap trannys... who knows. It would depend on wear/mileage of course to see if it works for both parties. Send me a PM if interested, and I will forward your info.

mikeforte · #6 (**permalink**) 12-19-2010, 07:30 PM

Hi Diego,
With your 3.42 rear gear and a 26" rear tire your car is at 67.8 mph at 3000 rpm. So in 5th gear with a .82 you'll be at 2460 RPM at the same speed.
50 mph = 1815 rpm
60 mph = 2177 rpm
70 mph = 2539 rpm
80 mph = 2906 rpm
90 mph = 3269 rpm
100 mph = 3630 rpm

With the .64 5th you'll be at 1920 RPM at the same speed
50 mph = 1415 rpm
60 mph = 1699 rpm
70 mph = 1982 rpm
80 mph = 2265 rpm
90 mph = 2548 rpm
100 mph = 2830 rpm

I hope this helps with your gearing questions. The gear & mainshaft swap are easy to do if you have done transmission rebuilding work before. I have instructions available if you need them.

mikeforte · #7 (**permalink**) 12-20-2010, 05:03 PM

Hi Diego,
I have a new TKO-600 .64 mainshaft & 5th gear available for just $275.00.

Excaliber · #8 (**permalink**) 12-20-2010, 06:56 PM

A taller FIRST gear ratio would be nice!! The typical TKO500 and T5's come with something like a 3.27 1st. An ultra low, stump pulling, tire smoking, all but worthless ratio (perfect for small blocks,,,,

).

The TKO600 is much better at 2.87, but still, not tall enough for my taste. A 2.78 ratio like the top loader wide ratio trans has would be ideal. I like the .8 OD just fine for my cam profile (2,000 rpm or higher) and rear gear ratio (3.31) that I'm running. .6 would certainly be to tall, unless I was looking for a speeding ticket.

I like to target my cruise rpm for between 70 and 75 mph to match the cam profile, tire size, gear ratio's, etc.

wideglidejoe · #9 (**permalink**) 12-21-2010, 08:03 PM

Hi Diego,

I don't know what engine combo you are running, maybe you feel like you need/want the 3.42's with the 2.87 1st gear in the 600?

Have you considered changed rear gear ratios? Maybe a 3.27 or 3.08 rear gear with the .82 would drop your RPM at cruise speeds. Again, maybe you need the 3.42's. But, in a light car, if you have enough low RPM torque, the 2.87 1st and 3.27's or 3.08's are plenty!

The original owner of my build had a 3.73 in the IRS, he was planning on a SBF/auto. I changed plans and went with FE/600 w/.82, so I changed from 3.73's to 3.27's, and I avoided the wide gap between 4th & 5th.

If you decide to swap 5th gears, Mike Forte is a fine guy to deal with! I got all my tranny stuff from him.

Good luck!

deckofficer · #10 (**permalink**) 04-25-2011, 06:02 PM

This winter I swapped out the Muncie M21 for the TKO 600. I wanted the tall gearing of the 0.64 because the current engine was built for torque down low, 516 lb/ft @ 2800, this pushing a car that weighs 1790 lbs. The picture says I'm geared tall enough for my taste. Last 1200 mile roundtrip netted 24.6, 30.2, 15.9, 28.2 mpg.

Mark IV · #11 (**permalink**) 04-25-2011, 06:17 PM

Quote:

Originally Posted by deckofficer

This winter I swapped out the Muncie M21 for the TKO 600. I wanted the tall gearing of the 0.64 because the current engine was built for torque down low, 516 lb/ft @ 2800, this pushing a car that weighs 1790 lbs. The picture says I'm geared tall enough for my taste. Last 1200 mile roundtrip netted 24.6, 30.2, 15.9, 28.2 mpg.

You shouldn't push those speed while the engine is not yet up to temp. The water gauge is on the low side for that load.

deckofficer · #12 (**permalink**) 04-25-2011, 08:31 PM

No T-stat and only 50 degrees outside. If I get through this summer without any overheating, the T-stat will go back in the Fall.

GT350Mike · #13 (**permalink**) 04-26-2011, 03:12 AM

[quote=deckofficer;1125095]This winter I swapped out the Muncie M21 for the TKO 600. I wanted the tall gearing of the 0.64 because the current engine was built for torque down low, 516 lb/ft @ 2800, this pushing a car that weighs 1790 lbs. The picture says I'm geared tall enough for my taste. Last 1200 mile roundtrip netted 24.6, 30.2, 15.9, 28.2 mpg.

What rear-end ratio are you running?

deckofficer · #14 (**permalink**) 04-26-2011, 08:44 AM

3.54 with 31" tires

Albie · #15 (**permalink**) 05-15-2011, 05:05 PM

Is anyone running a TKO-600 with a 3.07 rear? Is first gear OK? Not too tall? What size tires?

cobraman428 · #16 (**permalink**) 05-15-2011, 07:16 PM

I am running a FE engine with TKO-600 with 27" tires & rear is 3.08". First gear is 2.87 and is perfectly fine. 5th gear 0.64 is SWEET !!!!

mikeforte · #17 (**permalink**) 05-15-2011, 07:34 PM

Hi,
The 3.07 gears are fine with a TKO-600 if research the cam profile and speed in 5th. Lots of more radical cammed big blocks will need the .82 5th if the RPM is to low for the engine to run properly in 5th gear.
The choice of 5th gear is not a "one-size fits all". The 2 questions to you would be, what camshaft, carb & speed do you want to drive at?
Call me with any questions,

Quote:

Originally Posted by cobraman428

I am running a FE engine with TKO-600 with 27" tires & rear is 3.08". First gear is 2.87 and is perfectly fine. 5th gear 0.64 is SWEET !!!!

Albie · #18 (**permalink**) 05-15-2011, 07:53 PM

Thanks for the info. I'll probably go with the 0.82 5th, that will give me 70 mph at about 2250 rpm, which should be OK to drive home with. I'm having a 347 built, I haven't nailed down the cam yet, and want to use a 715 if I can find it. If not I'll go with a 650.