<VV> Corvair hesitation

[Jim Gammon]

Hi all, I'm a new member - 64 Monza HT 
 
I bought this Monza, and it needed a tune up, it ran when cold, but died when warm. I did everything but timing, I can barely read the mark on the block. It runs great now until completely warm, then it has a slight hesitation problem. It isn't really bad, but I want to fix it. 
 
Could this be timing? What else? I filled it with regular, but I hear no pinging.
 
It had decent plugs, some brown deposits.
 
Thanks in advance.
 
Jim Gammon
Manasquan, NJ