Hi steveinyuma; You've done a good job ID'ing everything. The "F54Y" engine is indeed a '54 Powerglide engine with hydraulic lifters. The 3701887 head decodes as a '53 and must've come off a '53 Powerglide engine since (if I remember right) that engine is the only '53 engine that had the "new" 18-bolt head. That should be an excellent match for your '54.

I kinda like the hydraulics. You just set-em and forget-em. I have a F54Y engine in my '53. They did make a bit more power than the regular engines and they are much quieter.

You're prolly going to get some differing opinions on this - some guys prefer the solids. After all, these are old trucks we're talking about here. Anyway, sounds like you've got 2 good candidates for projects there, maybe "his and hers" trucks, or maybe a cool retro Chevy coupe to go with your truck(?)