[fleming23]

It should definitely not be puking coolant at 190 degrees.

I would normally think you need a new cap but you mentioned trying two. Have you verified your temps with either an infrared gun or different temp gauge? You can pick up a cheap temp gauge at your local part store pretty cheap, or Summit has a variety of gauges you can order for not much $$.

Before anyone tries to convince you otherwise, you can absolutely cool a big block motor with electric fans. Many will want you to swap to mechanical clutch fans but that is traditional, I'd rather use points for ignition because it came that way 50 years ago, thought process. I look at that the same way I do those who say electric fuel pumps are no good on an old car. This too is bogus, but you can't just slap some cheap part on and expect it to work as well as something that was carefully engineered by a multitude of well-paid GM employees. You do need to CAREFULLY and thoughtfully plan out your cooling system while making sure to not skip any area. You need quality fans with good relays and wiring. These fans need to be mounted with some kind of shroud - this I suspect you lack. Many fans come built-in with a plastic shroud that mounts to the radiator and/or core support. They often have flaps to allow air to flow through at highway speed but close at idle so that you pull as much air across the radiator as possible. If you have two fans just quick-tied through the radiator and no shroud, you will very likely have problems.

Also, how do you have your fans programmed to turn on? Is there any type of relay/controller or is it simply a switch?

Again, I do not think at 190 degrees you should be seeing any coolant bypass the radiator cap. This still seems wrong to me as 190 is normal operating temperature, even 205 is not really overheating but is certainly warm (or warmer than I like to see my car get.)

Post some photos of your set up and maybe something will jump out.

When your fans come on, how hard do they blow? If you held a piece of paper either in front of the radiator (not as easy to do) or behind the fans, how hard does it pull/blow air?

EDIT - Why do you have a reverse flow pump? Is this a serpentine system?