Hey billV, solved the gas cap problem. With the original non vented gas cap and after market tank from Summit. Problem: the cam lock in the new tank is to high to seal with orig cap. Leaving the cap loose.
By cutting a new gasket from 1/8” rubber sheet (leaving the Inside diameter a bit tight so it won’t move around) I found it almost fit right. Still a bit loose. But cutting another gasket from 1/32” gasket material and putting it on first, (between the rubber and the cap) worked perfectly.
Now able to use the original non vented cap with the the after market tank!