I keep finding stuff my Pop bought years ago. Have the Rapid Cool kit & the Welmeister kit. Both old- note rust inside package of Weltmeister & the other says "Electrodyne" (blast from the past! ) Do these work? Are they worth it? Which one is better? Forget & try & unload on eBay ?

yes, it works, but only to the extent that it provides full flow of oil (no bypass) to the cam and lifters. It helped my hydro lifters stay pumped up, or pump up faster. The bypass is there for a reason, though. It reduces pressure on the cooler and seals when oil is thick, and probably some other things.

Which is better? Since the car is being converted to a GQ, sorry but I have no choice , will the oil ever get thick again? The only time she ever goes out is when it's nice out, period . I'm not very well suited to this CW thing

Weltmeister is the correct one. The other is for a Bug motor.

Actually the rapid cool kit is #10300 for the 356 & 912. Are those the older 912 engines they're refering to? Thanks.

yes, those are 1600 blocks. I fail to see a reason to install it. I like it as a period "accoutrement"- put it in the glove box, though.