Lets clear somethings up before this goes much farther,
1) Blow-by will not effect fuel system, ever! Blow-by is vented to atmosphere.
2) Fuel pressure build up in tank will flood the engine, NOT keep it from turning over. It will not cause it to hydrolock with fuel.
a) Hydrolock with fuel will cause oil to thin with fuel, oil to smell of fuel, and oil to be way over full, and likely low oil pressure.
3) Fuel pressure in tank is caused by bad vent or cap, you will notice pressure or vacuum when opening tank.
4) Fuel filters are never full, 1/2 or less is normal.
5) Battery cables should be as short as possible and 4 gauge or bigger. Bigger diameter is better.
6} Timing, dwell, points gap, do not change when hot. Timing can cause a hot start problem if set to high.
7) Crappy carburetors will not keep the engine from turning over, EVER. They make for hard starts or no start, but the engine will turn over.
8) Carburetors very rarely wear out and need replaced, but they do get dirty and need cleaned.
9) Vapor lock is fuel boiling, turning to a vapor and venting out carb.
10) Vapor-lock will NEVER EVER keep an engine from turning over.
Moving on, when the engine refuses to start when hot, have you tried to turn the engine by hand? Will it rotate or is it physically locked up?
Will the engine start when hot if you jump across the starter solenoid? ( Batt terminal to [ S ] terminal on solenoid )
Have you tried pouring water on starter when hot? If cooling it down causes engine to start, you have a heat soak problem.
Easy things to check,
Voltage at ( S ) terminal on starter solenoid when hot,
Voltage at starter with key in start position. Not at solenoid, but at point where voltage enters the starter case after coming out of solenoid.
Harder things to check,
Starter amp draw, hot and cold,
Hot battery amp test,
Hot cable amp test, similar to battery amp test only through cables to battery.
Ground cable should go directly to engine block with 3/8" bolt/stud and star washer. Frame and cab should be grounded from engine block or separate ground lead off battery. You CANNOT have to many ground cables or straps, BUT, you should only have one cable per terminal at battery with a solid crimp, not the bolt on DIY cable ends. Positive cable should be same size as ground, short as possible and run directly to BATT terminal on starter solenoid. Battery shut off switch should be able to handle 200 amps.
I see in the first group of photo's, the ground cable has the battery shut off switch installed, remove it for testing.
I also see you are running headers, does the starter have a heat shield? or heat wrap? Old headers create more heat due to thinning metal.
Joe
