Distributor Advancing

This may sound like a dumb question so here it goes. I have a 383 Ci with RHS heads i am not the builder or do i maintain the motor but having serious heating issues. The builder has the timing set a 40 degrees he says on the dyno the timing retards it's self 4 degrees. I personally can't see this possible but we can't keep the water temp below 240 has anybody ever heard of a distributor doing this i'm pretty sure it's advancing and causing the heating issues. Also it is a stock HEI locked down.

Depending on the chamber design, even 36* is too much. A good fast burn chamber will only want 31-34*. I can nearly guarantee your timing is a large part of your over heating, may not be the whole problem but definitely not helping.

40 is crazy on a sbc.

I've seen motors that would retard at rpm.The timing was set high at idle and fall back at rpm, never cause problems.A cam button and realignment of the timing gears helped it.

Does it have an HEI distributor in it? Ive seen the timing back up many times on the dyno, and its usually with a locked up dist. The ignition module can effect this, so can the distributor end play.

If this engine was tuned on a dyno then I would also guess the fuel and jetting was tuned and they were OK with the numbers they seen. I'm betting the timing is not your problem. Eric

Do you know what the oil temps are? That might lend a clue whether the overheating issues is engine tune based or simply a lack of heat transfer from water to air. 1st thing is to verify the gauge is accurate because you don't want to be chasing a phantom problem. I'd put a coolant system pressure test on it and make sure it's not losing water from a head gasket or cracked block/heads.

Is this on the track at RPM or idle speeds too?
Radiator clean and has straight fins?
Is the fan moving enough air across the core?
Shroud?
Slipping belts?
Is the water pump moving the water fast enough?
Is the cap holding pressure?

I would back timing down under 36. Also you may have to change pulleys or restrictor in thermostat housing