As far as I know there was not a 336, A 236? 236& 256 were limited production short deck engines. While a 248 would not be a bad choice. A rebuilt 270 Shortblock for $1000 isn't a bad rice if done well. I doubt if you could redo yours for that + time.That's where I'd go.

"I wonder if God created man because he was disappointed in the monkey?" Mark Twain