Engine Masters Competition featured Ted Eaton's 375 c.i. Y-Block, so they can be improved upon to be performance and reliable.
I would recommend trying to find a '57-'64 292 block to start with, along with a '57 -59 ECZ-G or 113 Heads to have decent compression. Skip a 272 if you can. They can be made into a 292 easy though. Stroke kits are availbe for 292 to make them work much better. Its just like stroking a 460 as bigger is always going to be better in the end.
Start watching the Y-Blockfoever forum to get some ideas to make it run good, so you enjoy it as well.
If you tell everyone you know you are looking for a Y-block they will start showing up for you. They have a ton of character and will be worth all the effort in the end
69 Mach1 R -Code 428 CJ,Red 4spd
69 Talladega 428 CJ,Maroon
69 Boss 429 Mustang
70 Torino Cobra 429 SCJ 4spd 4:30 Drag Pack
69 Bronco 5.0 F.I.
57 Ford, VR57 Supercharged 312
57 Ranch Wagon 5.0 AOD
57 Ford Courier Delivery
57 Ranchero VR57 Supercharged 312
57 Thunderbird, 460/C6