Stan,
if you only plan on driving down back roads & only going 40-50 MPH, I would just use a 2400 Stall tops, with having a 3:06 first gear & 3:73 gears, & a 292 pushing it to go, , you should have no problem with it being able to take off quickly.

How much does your 46 Chevy weigh, 3000 LBS?

You do not seem too concerned about being able to 60 ft the fastest so, just anyone of those off the shelf converter would be fine to use IMO.
Example: http://www.summitracing.com/parts/hup-22-25
Just make sure to get a lock-up converter as I stated before.

Here is a B&M: http://www.summitracing.com/parts/bmm-70419

Having a stall in the 1600-2100 range is not worth even getting IMO,.
Having a Lock-up converter & having a higher stall, the best of both worlds. grin

It took forever for Tlowe to listen to me to get a higher stall converter for his Elky, he still did not get what I suggested, but it is much better than what he had initially.

MBHD

12 port SDS EFI