When an engine is seasoned it means that ALL things inside are OK. As far as valves/seats go just driving the car seasons the valves & seats through induction hardening. It means the engine has had time over time to harden things as it goes through the process of heating & cooling. When the heads are removed for re-conditioning is usually where the problems come in. SO, IF it's still original I wouldn't worry about it just add the additive for more of peace of mind other than anything. Just my thoughts on the subject. Tom T.
Thanks Tom, since i don't drive it that many miles a year and certainly don't race the engine i think i am not going to add anything but fresh ethanol free gas which we still have here (still...)
I owned, from new, a 1970 Malibu with 350-4v. The car was built in April 1970> I was informed that the heads at the point in time had hardened valve seats.
Highly doubtful... 72 77 & 81 chevy 350 that I know were one owner motors did not have hardened seats.. Chevy also claimed they started to put roller cams in their SBCs in 86. LO3 -LO5 . Ive pulled enough of those apart also never saw a roller yet..
Ok did a bit of reading Lo3 & 5 car motors have the roller cam. Not the truck. Way to go Chevy And people wonder way I hate Chevys and own 2 of them.. FWIW. 350 boat. Other is a 92 caprice with a TBI not the junk LT1