Hey Scotty,
I have a BEAUTIFUL 1979 Firebird Trans Am Special Edition with 54,000 original miles on it with the number matching olds-403. Because synthetic oil can be harmful to the seals within the engine. What oil or additive would you recommend to with a detergent to help clean out any sludge that has possibly built up over the years. I have been using Pennzoil as it has been known to have the least amount of polymers, which will then produce the least amount of ash out of all the conventional oil’s however, what conventional oil would you use or recommend to use in this old of an engine?
Thank you for your time
Justin
@justintrader Please do not "hijack" someone else's topic to ask your question, create your own topic instead.(Your post has been split off into its own topic.
Synthetic oils do NOT damage engine seals. I run synthetic oil in cars over 50 years old with no problem. You should not use any additives, virtually all are snake oil that do nothing but empty your wallet. There are "boutique" oils formulated for classic cars sold by Hemmings and others you could consider using if concerned.
https://www.hemmings.com/classic-oil/
