TKO 500 or 600?

[usc2001gc]

Well, it looks like my deal on a T-56 trans for my 71 chevelle fail thru. So I guess I'll be putting a tko 500 or 600 in my car. The question is, which gear ratio (500 or 600) would be best for my combination. I'll be running a mild 402 BB, with a 2.73 rear (if the code is correct on my axle housing....need to pull the cover and check the actual gears before I order the trans.) I'm leaning toward the tko-500, due to it's 3.27 first gear ratio. I'll probably leave the 2.73 in the rear and maybe enjoy some fair gas milage.

Also, I was considering a hydraulic TOB, does anybody make one for the TKO that's more affordable than the McLeod (~$375.00)? Or should I stick with a mechanical system.

[Hurst - Jeff]

I would go with the TKO500 if you want the first gear pop but the .68 overdrive will be very deep.
The other option is a TKO600 with the .82 overdrive if you are focusing on the 5th gear.
I would go with themechanical linkage unless you just have to have hydraulics - easier and less expensive.

[JoshC]

Is your car a manual transmission now, or is this a conversion?

[usc2001gc]

This is a conversion. Originally auto on the column.

[dhardison]

The easiest way to check the differential gear ratio without pulling the rear cover is to lift the rear end of the vehicle with a jack (using jack stands of course) and physically rotate a rear tire one complete revolution while counting the number of revolutions that the driveshaft/pinion makes. If the drive shaft rotates almost three times, your differential gear ratios would be 2.73:1, etc. Obviously it's not as exact as counting the R&P teeth, but it'll save you pulling the rear cover just for that purpose.

I'm running a TKO-500 (.68 5th, w/3.42) with my 454 and LOVE it. With the 500 and your 2.73s you'll be pulling a 1.85:1 final ratio, which might lug in 5th at lower speeds, but you'll love that .68 if you ever go with a numerically higher gear. My car runs ~2100@70mph and I average 16-17mpg on the highway.

As Jeff mentioned just go with the mechanical linkage. In my opinion it gives a better feel than hydraulic.

Dan

[Kenova]

The easiest way to check the differential gear ratio without pulling the rear cover is to lift the rear end of the vehicle with a jack (using jack stands of course) and physically rotate a rear tire one complete revolution while counting the number of revolutions that the driveshaft/pinion makes. If the drive shaft rotates almost three times, your differential gear ratios would be 2.73:1, etc. Obviously it's not as exact as counting the R&P teeth, but it'll save you pulling the rear cover just for that purpose.
Dan
If the diff. oil has never been changed, then it might be a good idea to pull the cover anyways. The factory gears may also have the tooth count for the pinion and ring gear stamped into the edge of the ring gear. From there it's simple division to get your ratio.
Ken