The engines in my 1968 31 Commander Sedan were rebuilt by the previous owner and now have about 150 hrs on them. Standard stock cams as far as I can tell. Do you guys out there with these small block engines add anything to compensate for the lack of lead in the fuel?
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I have 427’s. I add a lead substitute and an octane booster. If your marina has valvtec in it you don’t need to. Your concern is the valve seats in the heads. If they replaced them during the rebuild you have no worries. If not, use an additive
I have 350Qs also. I use ethanol free unleaded gas with no additives.
Same here. A 350Q from circa 1990 is in my 27. I ran it on Valvtect with no additives, no problems.
Hopefully they put hardened seats in for the exhaust valves when they did the rebuild. Marine fuel was still allowed to use lead well after it was banned for automotive use and the marine industry lagged behind in using hardened valve seats (probably lots of NOS heads awaiting assembly). I have mid 80s BBCs and use Lucas Upper Cylinder lube just in case, plus it may help to prevent valves from sticking over lay up.
Thanks for the tip