1970 350/300 fuel requirements
 

If I run Gum-Out or some equivalent through the engine, followed by an oil change with Slick50; can I use unleaded premium without any problems?

Should run on unleaded premium without doing either of those two things.

I have a 350/300 with a 350/350 cam and have been running unleaded premium for the 30+ years i have owned it. No problems. I think you are talking about an oil flush and an oil change with additives. Not sure how this would help fuel issues. For the oil, I would use a high zinc content oil if you are running the stock flat tappet (or any flat tappet) cam. Off-the-shelf oils don't have the zinc content they once did and don't protect the cam as well as the older formulation oils. Are you having fuel issues?

they still sell that stuff?

lol :-)

Really, good to know; as you might guess, I have not owned a vehicle that use to run on leaded gasoline. And have also heard you need to use a lead additive or install a 'conversion kit'. Thank you for a quick reply.

Good to know; as you might guess, I have not owned a vehicle that use to run on leaded gasoline. And have also heard you need to use a lead additive or install a 'conversion kit'. Thank you

My question is why would you put Slick 50 in it? ask any rebuilder what that crap does to the inside of your block. use a quality motor oil suitable for flat tappet cam and leave the snake oil to salesmen

OK, thanks for the input; much appreciated.

Thanks did not know about the "zinc content" you mentioned.