I have no read out on my temperture cluster replaced blower motor module and it didn't work can't adjust heat temerture just blows high cold air

I put a new starter on put the problem came back.also when the car warms up it misses bad.this does not happen when the engine is cold.i replaced all electronics.mass sensor crank sensor cam sensor.when warm putting in neutral
Doesn't stop it from cutting off at lights

what octane gasoline is best for my super coupe 1995