ctbs99xc

Got a 85 wellcraft nova with a 5.7L what weight oil should I use in he motor? 20w-40 or 10w-30

jeffswav

Auto oil has removed a lot of the chemicals needed for the flat tappet cams. If you want a cheap oil try the Rotella diesel oil 15/40. If you want somthing better try Amsoil Marine/Diesel oil 15/40.

minxguy

Where are you buying 20w40?

Use a good motorcycle oil.

Tons of zinc.

Ken