I did this exact deal on my '62 Suburban (and wrote a story on that transmission for Custom Classic Truck a year or two ago).

It's the same drive gear and housing as a 700R4 or TH350.

Speedometer World
(888) 877-1008
Central time, open until 5pm.

They had them at reasonable prices (especially compared to the local Chevy dealer).
They have a calculator on their website that tells you what drive gear you need based on tire height and rear end ratio. I've got 3.42 gears, 29-inch tall tires, and a 40-45 housing. I needed a 43-tooth drive gear.

Now, my speedo MPH is off, but my odometer is accurate almost to the foot, according to GPS and highway mile markers that were spaced every 1/10th mile. My speedo needs to be recalibrated, rather than the gear needing to be redone.

Hope this helps.
-Brad
by the way--the best $100 you can spend is to have the original Hurst shifter sent back to Hurst for a rebuild. Maaaan you won't believe how nice it is! Also, if you need a new tailshaft housing seal or trans yoke, it's also the same as TH350.


SOUTHERN FALL GABfest
October 6 ~ Commerce, Georgia
Details here!


Never Pee on an Electric Fence.