I have used Melling assembly lube with good results for several engine builds. It's a thick red liquid with just a little bit of stickiness which sort of reminds me of STP. BTW, every one of the engines I've built using STP as an assembly lube have had some sort of oil-related problem. Maybe it's just a coincidence, but I haven't used that stuff since the mid-1960's in anything other than chainsaw bar oil.

This product with the Permatex brand name looks like the same stuff:

https://www.amazon.com/Permatex-81950-Ultra-Engine-Assembly/dp/B000HBNVSK

Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!