Here is where I buy mine, but local auto stores generally stock it a s well.
One small bottle per oil change.
The Sea Foam can has a ratio on it, but I think it's about half a can per tank of gas (if my memory is correct)
I don't think extra will hurt anything.
And try to fill the tank totally full to not leave a void for condensation to form inside. But at 50 degrees, that probably won't be an issue.
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 LE (No Burt) 1976 T/A New baby, starting full restoration. 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1968 400 coupe - R/A clone (Blue Pearl) (sold) 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold
