Who is happy with their TKO600 with 0.64 O/D?

[AC Ventura]

Who is happy with their TKO600 with 0.64 O/D?

I know this has been done to death, but now it seems it my turn.

It seems the first 4 ratios of the TKO are quite similar to the original Toploader, so I guess the question is when you shift at 4000, with in my case with a 3.54 rear end will be 90mph, surely the 0.82 with its progressive 5th gear is a bit of a luxury. Seems to me, better to have the 0.64 option and get some quieter and more economical cruising. I'm guessing this will be a bigger real life benefit than accelerating hard from 90.

Trouble I see a lot of posts from guys, who want to trade there 0.64s for a 0.82s. I'm wondering if they have a longer rear end such as a 3.31 or 3.06?

Motor is a 427 FE approx 480/500 etc. Comments and real life experiences would be very welcome.

[jhv48]

I'm in southern calif. and I have a very streetable 427. We have lots of freeway traffic and I found myself constantly rowing between my overdrive .64 fifth gear and my 1:1 fourth gear slowing from 70 down to 60mph then back to fifth when traffic opened up. With my 3.56 rear gear, my fifth gear was useless below 70mph. In order to pass quickly, I would have to downshift back to fourth.
Finally got tired of losing 1000 rpm when upshifting to 5th. Sold the tko 600 and had Gordon levy build me a super alloy t-5 with a .80 fifth speed. Strong enough to handle my 550 lbs ft of torque and much smoother shifting.
Now, I cruise at 70 mph at about 2600 rpm. 60 mph is around 2200 rpm so I never need to downshift when traffic slows. Need to pass at 70? Just step on the gas. Immediate torque.

Wish I had done this from day one!

[keezling]

Get the six speed with both of ratios, or a vairable ratio trans! Drove some v.r. equipped cars. Has to be the suckiest trans ever invented!!! I have the .64, wish I had the .82. If I had the .82, I'd want the .64. Human nature.

[AC Ventura]

Originally Posted by jhv48

I'm in southern calif. and I have a very streetable 427. We have lots of freeway traffic and I found myself constantly rowing between my overdrive .64 fifth gear and my 1:1 fourth gear slowing from 70 down to 60mph then back to fifth when traffic opened up. With my 3.56 rear gear, my fifth gear was useless below 70mph. In order to pass quickly, I would have to downshift back to fourth.
Finally got tired of losing 1000 rpm when upshifting to 5th. Sold the tko 600 and had Gordon levy build me a super alloy t-5 with a .80 fifth speed. Strong enough to handle my 550 lbs ft of torque and much smoother shifting.
Now, I cruise at 70 mph at about 2600 rpm. 60 mph is around 2200 rpm so I never need to downshift when traffic slows. Need to pass at 70? Just step on the gas. Immediate torque.

Wish I had done this from day one!

This seems pretty definitive!

[Jim Vander Wal]

In a previous car I had the TKO-600 with the .64 OD and a 3.27 gear. Only time I didn't like it was 50-70mph back road cruising in 5th so I just drove faster or ran in 4th. New build will be same motor and trans and 3.31s.
Jim

[Grubby]

My last Cobra had a mild 428 stroker with 3.54 final and TKO with .64.

Fantastic set up for cruising above about 60mph. I would definitely do the same setup again.

John

[vatdevil]

3.30 gears with 427 Windsor built for street use 560 HP/620 ft/lb. 5th gear is good from 55 mph. Great highway cruise setup.

[Kit Coyle]

I have a BOSS 302 with ~400hp, 3:31 rear and a TKO with .63 5th.
The TKO 1st is 2.95 vs 2.87 in the TKO 600 so the 3:31 rear keeps the 1st
gear from being too short. The engine revs to 7000rpm+ so I mostly only
use the first 3 gears at high speed on country roads. 4th gear is mostly for
the occasional freeway use and 5th only for long distance at high speed on
the freeway. Basically it is a 4 speed with an overdrive gear. I bought the
car from the first owner in San Diego and drove home to San Francisco... so
my first drive was 7 hours on I-5 at 80 mph! The .63 5th was great...a nice
quiet drive at ~2200rpm. I'd love to try a .82 5th as it would be a better
sequential gear [less rpm drop from 4th to 5th] but it would still only be a
freeway gear and I wouldn't use it much.

[blykins]

With a cam that has any amount of overlap whatsoever, .82 is the only way to go, unless you want to play the bucking game.

I have sold probably 2 .64 TKOs since I've been in business. I have no use for them, or a Magnum T56 for that matter.

[olddog]

I have a .64 5th in a TKO 600 behind a 5.0 stroked to 347. It had a 3.50 rear and 26.3" tires. Cam is 236/242 duration at 0.050" lift and a 110 lobe separation angle.

4th gear 2550 rpm = 57 mph -- this is a bit too load to talk.
.64 5th is 1632 rpm @ 57 mph -- cam does not like this at all.
.82 5th is 2091 rpm @ 57 mph -- this is perfect in my mind.
.82 5th is 2400 rpm @ 65 mph -- too much wind to talk anyway.
.82 5th is 2550 rpm @ 70 mph -- too much wind to talk anyway, but this is same as 4th 57 mph.

If you have enough low end torque, a little taller rear gear would work well with a .82 5th gear.

I had to rebuild my rear end (pinion bearing), so I swapped out to a 3.92 ratio.
.64 5th is 1835 rpm @ 57 mph -- cam is happy.
The problem:
4th is 2850 rpm @ 57 mph -- Way too loud to talk, now useless to cruise with.
2100 rpm in 5th is 65 mph
2250 rpm in 5th is 70 mph

So bottom line, the 3.93 rear gear makes 5th OK, but I still hate with a passion the huge step down in rpm when shifting into 5th. I cannot say enough times how much I hate this. Not to mention that 1-4 are too low now. I like the 3.5 ratio much better, in the lower gears.

I will eventually change to the .82 5th gear and have the synchronizers upgraded. I will most likely go back to the 3.50 gears.

Let me say again 6900 rpm in 4th gear will drop to 4400 rpm in 5th. This sucks, sucks, sucks, and I hate it, hate it, hate it.

I have read where some fellows with big blocks, like the .64 for highway cruising. I suspect mild cams, too.

All I can say is, if you want a .64 for highway cruising, then buy a 6 speed.

[Kit Coyle]

I agree with the Old Dog on the RPM drop when going from 4th to 5th with a
.63 5th gear. The RPM just falls off a cliff...it almost feels like you are short
shifting...like you skipped the next sequential gear. For my 7 hour 80MPH
drive from San Diego to San Francisco it was peaceful but that was two years
ago and I haven't used 5th gear since! Too bad it isn't easier and cheaper to
change. For all I know it may not even be possible with the original TKO?

[gthompson]

Originally Posted by AC Ventura

Who is happy with their TKO600 with 0.64 O/D?

I know this has been done to death, but now it seems it my turn.

It seems the first 4 ratios of the TKO are quite similar to the original Toploader, so I guess the question is when you shift at 4000, with in my case with a 3.54 rear end will be 90mph, surely the 0.82 with its progressive 5th gear is a bit of a luxury. Seems to me, better to have the 0.64 option and get some quieter and more economical cruising. I'm guessing this will be a bigger real life benefit than accelerating hard from 90.

Trouble I see a lot of posts from guys, who want to trade there 0.64s for a 0.82s. I'm wondering if they have a longer rear end such as a 3.31 or 3.06?

Motor is a 427 FE approx 480/500 etc. Comments and real life experiences would be very welcome.

I have the same set up as you and I have been going back and forth about going with the .82 or .64 OD
I have been reading a ton of posts from here over the last year
I have a 427 aluminum FE (505 Hp) and the 4 speed top loader with a 3.54 rear end

At 70-80 mph the engine rpm is way to high

With the 4 speed top loader:
At 60 mph -3000 rpm
At 72 mph -3500 rpm
At 85 mph -4000 rpm

I took a video of my speedometer and the tach while I was driving
The rpm might be off by 100-200 rpm either way

The video is a little hard to see really clear, the car was shaking and vibrating a lot Lol

I brought my car to the shop in Dallas 2 weeks ago to have the TKO 600 with the .64 OD installed

It should be ready in 1 week

Hopefully it was the right decision

[AC Ventura]

Thanks guys for all the responses. I expected the answers here to be clear cut but they are not. Both camps have their supporters and in an ideal world I'd try both gearboxes in my car. But that's not practical. Hitherto, I have decided, that the car is about performance as a primary. In that case the progressive gearing of the 0.82 won't disappoint. If it's too low geared with my engine, I have the option of dropping to a 3.31 rear. So I've gone with the 0.82 and won't know if the 0.64 attributes would have served me better, from a practical perspective. But the engine builder, urged me that with my cam, the 0.82 was the better choice, so that sealed it.

[mdross1]

My car with 460 using the .64 is perfect even lugging down in 5th the engine has enough grunt to pull like a freight train. Of course it can only be lugged down so far before the cam starts making itself known. Rear gear is a 3:70. Before the change had a top loader with a 3:55 gear and always wanted one more gear for cruising.

[joyridin']

If you have an EFI car without a massive cam, a T56 is the way to go especially if you do a reasonable amount of highway driving. You get both options of the TKO. I would not use it with a carbureted car because you will probably never get into 6th gear without making first gear something akin to the old granny gear in a pick-up truck.

I have 3.7 rear gears, a .54 6th gear, and 26.5" tires and it works great through the whole range. 4th is great around 40mph, 5th is great for around 60, and when I get on the highway and do 70 or 80, you click it in 6th for cruising. Shifts smooth as glass, multiple shifter locations, and you can use a cable for the speedo.

[jhv48]

If you plan on doing a lot of driving between 70-80 mph, get the 3.31 rear end. You'll still be in your engines power band, but you'll be turning a couple hundred rpm less.

[olddog]

Originally Posted by gthompson

I have the same set up as you and I have been going back and forth about going with the .82 or .64 OD
I have been reading a ton of posts from here over the last year
I have a 427 aluminum FE (505 Hp) and the 4 speed top loader with a 3.54 rear end

At 70-80 mph the engine rpm is way to high

With the 4 speed top loader:
At 60 mph -3000 rpm
At 72 mph -3500 rpm
At 85 mph -4000 rpm

I took a video of my speedometer and the tach while I was driving
The rpm might be off by 100-200 rpm either way

The video is a little hard to see really clear, the car was shaking and vibrating a lot Lol

I brought my car to the shop in Dallas 2 weeks ago to have the TKO 600 with the .64 OD installed

It should be ready in 1 week

Hopefully it was the right decision

Yes your rpm is accurate give or take 200, as I can make those numbers work within that range. Assuming the 4000 rpm 85 mph is the most accurate number and assuming the 3.54 rear gear is a fact, then I calculate a 25.3" tire.

I also calculate 1800 rpm will give you 60 mph with the .64 5th gear.

If the 3000 rpm 60 mph is correct then you have a 23.8" OD tire and 1920 RPM will give you 60 mph.

[gthompson]

Originally Posted by olddog

Yes your rpm is accurate give or take 200, as I can make those numbers work within that range. Assuming the 4000 rpm 85 mph is the most accurate number and assuming the 3.54 rear gear is a fact, then I calculate a 25.3" tire.

I also calculate 1800 rpm will give you 60 mph with the .64 5th gear.

If the 3000 rpm 60 mph is correct then you have a 23.8" OD tire and 1920 RPM will give you 60 mph.

Sorry
I forgot to mention the tires
I have the Goodyear Billboards
I believe they are 26" OD

[Large Arbor]

Ok, so I have a 427 with a milled cam and a TKO 600. It tach's nearly 2800 rpm at 65 and is loud enough to be painful on a long drive. I do not know what the trans ratio is but I have a 3.54 rear end. Should I pull the trans and switch the 5th gear? If so, to what?

Phil

[rodneym]

AC Ventura,
In my Kirkham I have a TKO600/.82, 3.42 and the cam has legs.
In my Shelby (Street 427) I have a TKO600/.64, 3.54 and the cam is milder than most.

The .64 only makes sense if you can cruise in the mid to upper 80's. With the Shelby's cam I can cruise at lower rpms. On the Kirkham it would be a no-go, rear ends notwithstanding.

In other words, if the .64 was in the KMP, I'd be bummed.
You'll get quieter and more economical cruising with the .64 but you'll be movin'. The cam will tell you what it wants.