[Farmall] 53 Chevy pickup

[Richard BROWN]

Looking for ideas about my wonderful '53 Chevy 3/4 ton pickup with 235 engine:  When the engine gets hot, it does not want to start.  If I hook up my battery booster to it, it turns over very fast and starts.  It has a new battery.  

Why does it NOT turn over fast enough to start when hot?  While running, it runs like a top, has tons of power.  I've had the starter rebuilt, the carburetor rebuilt, electric fuel pump installed, but it still needs a boost when hot.

Richard Brown  Horton Bay, Michigan