Welcome pappy, I think your choice of engines should reflect how important originality is to you, and what expectations you have. What do you want from it, to make power or just cruise around? If you don't mind it not being exactly original then the 292 is cheaper to build, and parts are easier to find. The general consensus here seems to be that 239's and 12volt conversions are the only way to go. That is their personal opinion only. I have driven y-blocks most of my life but never had a 239 until this year. I also don't mind the 6volts, it starts fine. If and when it needs very much work I will go with a 292 because of parts availability and price. A little more power doesn't hurt either, but it is fine like it is for how I use this vehicle.
Here is one source for engine kits for 272, 292, and 312 engines only.
http://www.ford-y-block.com/enginepa.htm
Tom from the chiggerfarm located in the beautiful Heart of Central Texas
When you cannot dazzle others with your brilliance, baffle them with bullcorn! 