I have a 1991 camaro z-28 with a TPI 305 V-8.

It was rebuilt at 50k miles and the distibutor has been replaced once and now again it needs replacing again based on the conversation with the previous owner. its starting to skip again and once it reaches operating temperature if its turned off it wont crank again until the engine is cooled off

the car has about 20k on it since rebuild and it was rebuilt back to factory specs no high performance parts

can you tell me what the problem may be

I wonder what your spark plugs look like.

the spark plugs are clean no build up

It looks like there isn’t much interest here. Most distributors last a lot longer than 20,000 miles. Some people use really old ones and don’t give it a second thought.

Not starting when warm can be that the choke thermostat is old and not working properly. Your ignition module may be done for. Take the ignition wires off the distributor cap and look for damage to the cap. Check the center electrode (which can break) that contacts the rotor and check the rotor for a bent tang. While you’re there you might as well change the coil too. Don’t mix up the #5 and #7 plug wires.

…“once it reaches operating temperature if its turned off it wont crank again until the engine is cooled off”

There is a definitive difference between CRANKING and STARTING.

If you really mean this engine “won’t CRANK” untill it has cooled off, then this is a starter/solonoid heat soak problem.
I had an 85 Z-28 IROC w TPI and it had the same problem. The solonoid is experiencing “heat swelling” from the exhaust and engine heat, so it won’t engage the starter untill it has cooled off. The solonoid plunger swells up and sticks inside the cylinder and can’t move, untill it cools off and again regains the necessary clearance to slide in the bore.

You may have an additional distributor problem, but my '85 had 168,000 miles on the ORIGINAL DISTRIBUTOR when I sold it, so don’t jump for the distributor too quickly.
You might try the other posters sugestions plugs, wires etc for the “skipping” problem before you spring for another distributor.

thats good information
i will check it exactly how you told me and i will let you know if those things worked
thanks alot