46 minutes ago, w3wilkes said:

Does this coincide with A/C compressor engage / disengage?

Or electric fans coming on?

Friend, turn the car on let it idle for how ever long it takes for ac clutch engagement/aux fan engagement. Then check your tach. If the hood is open it’s going to take longer for the engine to heat up and fan to engage. Spend some time into watching and listening to what the engine is doing. Sitting in traffic and trying to figure out what’s happening is impossible to diagnose. Not sure what you’re asking here other than the components that create amperage draw on the alternator which directly coordinates with rpm dropping. Modern cars have a solenoid that bumps the throttle up when the ac is engaged. My two cents.

7 hours ago, w3wilkes said:

Does this coincide with A/C compressor engage / disengage?

7 hours ago, w3wilkes said:

Does this coincide with A/C compressor engage / disengage?

This has nothing to do. Rpm falls to 500 ramdonly once the temp reaches 3/4 of the gauge. Id like to know if this is due to something inside the engine or the MSD ignition coil or else?? Unfortunately 70 years old Camaro expert mechanic quit helping me and offered to return money paid for not solving this issue. Are we ready to open the engine?

You continue not to answer questions/guidance and suggestions for the tests we have presented and asked for. You’re not contributing on your end to diagnose the problem.

4 minutes ago, Yarb said:

You continue not to answer questions/guidance and suggestions for the tests we have presented and asked for. You’re not contributing on your end to diagnose the problem.

What queries would you like to be answered? I paid a 70 year old expert to fix my car and he went around the bushes! Whats left?? Open the engine to see whats causing the problem when the engine reaches.3/4

Opening the engine is unlikely to show why your engine rpm drops randomly. That's not going to be an internal problem in my opinion

Who's going to open the engine? The Camaro expert hiding in the bushes?

14 hours ago, Yarb said:

You continue not to answer questions/guidance and suggestions for the tests we have presented and asked for. You’re not contributing on your end to diagnose the problem.

14 hours ago, Yarb said:

You continue not to answer questions/guidance and suggestions for the tests we have presented and asked for. You’re not contributing on your end to diagnose the problem.

Yarb,

What questions would you like to be answered? I thought paying a Camaro carburertor expert mechanic would solve the problem. It didnt! Now the only way would be depending on your help overseas.

I look forward to your input.

8 hours ago, siteunseen said:

Who's going to open the engine? The Camaro expert hiding in the bushes?

8 hours ago, siteunseen said:

Who's going to open the engine? The Camaro expert hiding in the bushes?

8 hours ago, siteunseen said:

Who's going to open the engine? The Camaro expert hiding in the bushes?

Site,

No way im spending more money on trial by error mechanics in Panama. Guess work is not leading anywhere.

Don't forget the build sheet from California Datsun. @Yarb needs to know all this before he can help you overseas.

2 hours ago, siteunseen said:

Don't forget the build sheet from California Datsun. @Yarb needs to know all this before he can help you overseas.

Just to add to this car has no Far 311 Cam now. It was replaced in 2014 with a Schneider 274F cam incluiding new retainer springs and full kit. Current ignition coil is an MSD in combination with petronix ignitor 1761 module. So no points.

Is that when you started having problems or were your problems the start for these changes? Which came first, the problems or the cam and new ignition? Why did you change cams and who did the work? The Porsche mechanic? Why the new ignition and who did that work?

There's no rhyme or reason for the work you paid the "trial by error mechanics". I think you are doing trial by error, lack of research and not using the information that's been provided to you.