Won't start when up to temp

Do you have points in the distributor or a points conversion? If it’s a conversion which one?

 

No the distributor isn't locked

 

Hei

 

If when cranking hot you have spark that will trigger a timing light then I would rule out any issue with the HEI

 

Ehhhhh...not my first guess.

I like to prove spark power by using a spark tester calibrated for HEI. Has a bigger spark gap than testers suitable for ignitions with ballast resistors.

Example:
https://www.amazon.com/dp/B003WZXAW...KC3HBBDO&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

HEI spark tester has recessed center electrode for a longer spark gap. Ballast-resistor style spark tester has visible center electrode. These testers, when used at the spark plug end of all the plug wires, will verify the entire ignition system EXCEPT the actual spark plugs--which could be fouled. When used at the plug end of ONE wire, will verify all the parts of the ignition system that are common to all cylinders--primary wires, coil, distributor including ignition module or points/condenser but not the cap or the other plug wires.




Above all, DO NOT TRUST a spark tester that has a stupid light-bulb that glows--neon, LED, etc.




If the engine "has spark" and "has fuel" and "cranks normally"...are you tapping the gas pedal ~1/4 pump (maybe less) before cranking to wet the intake manifold a little? Does the accelerator pump work?