George,
First, making an adapter plate for the tranny to 46 bellhousing won't be necessary (like in the Stovebolt article) as Buffalo allready makes one for $120.
Second, the 55-62 truck center section can be used, but 3.90 and 3.36 were the only gears used. 3.36 can be bought new from Patrick's or Randy's ring and pinion, plus others.
Using a whole 55-62 truck rearend can be done, but it's several inches wider that the '46, so this may be an issue with you depending on the rims and tires. The '46 brakes are different than the '55-up, also. Changing the spring perches is still necessary.
To fix the rearend in place, Speedway Motors (and others) sell some spring perches for $12.95, see part #54585090 over at
www.speedwaymotors.com . Remember that the rearend is not centered over the spring center bolt!
You'll need to come up with a driveshaft. Probably have to find one thats a little long and have it shortened and the rear yoke changed to match your rearend yoke.
Personally, I would go with what Joe suggests, and use a 55-64 car rearend. It's a little less work, no expensive aftermarket gears needed, 3.36 and 3.56 geared centers are readily available used. New wheel cylinders and shoes will run about $35 for comparrison.
