Go with Fel-Pro MS98014t. Available at any parts store that carries Fel-Pro gaskets. Do yourself a favor and get the aluminum coolant elbows at the same time.

The lines come in 8,12,20,30,40,51, & 60 inch sections. You have to connect them with the metric bubble unions. The alternative is a 25 foot roll of 3/16" line, the correct nuts, and a good bubble flare tool.

Compression unions are low pressure fittings. Say, 500 PSI max. Modern brake systems can generate 1200-1500 PSI or more in a panic stop. That's why you should always use the proper ready-made lines and the proper unions for them. Any decent parts store will have what you need to repair it.

I run NGK TR55's and Belden wires from NAPA. I have no reason to change.

It still sounds like the CPS or the wiring to it. Have you checked for spark or fuel pressure when this occurs?

It may be something as simple as the Crank Position Sensor. Classic symptoms.

I can highly recommend Philips Xtreme Power as a great upgrade.

I would also check the fuel pressure regulator. Pull the hose and sniff for a gasoline smell.

Sounds like the crank sensor. A very common heat related failure.

The oil pressure sender is a common leak point.

It does sound like a cps to me also.

Mine is in the trunk mounted next to the right rear speaker. This is on a 95 Riviera.

If a good tune-up doesn't cure it, you may want to check the injector or in an unusual but not unheard of case, a broken valve spring.

If it's never had the crank sensor changed, that's what I would suspect.

I would suspect the crank position sensor from your description. It should start and run fine till you get it home but it's only going to get worse. Once they cool down they work as they should.

I remove the lines at the back of the pump, not down on the rack.

Test the temp sensor for the PCM.

It's very likely a bunch of coolant got into the exhaust and will take time to burn off. Head gaskets are almost unheard of in these engines.

Sounds like a crank sensor issue.

The compressor cycling sounds pretty normal. You may have one or more actuators that are lazy or inop. The idle prob could be a number of things. IAC, vacuum leak, TPS, or carbon buildup in the throttle body.