I have a 350 in my 1986 silverado. I wanna start beefing up the engine by setting it up to run 100 octane or possibly 100LL since its readily available to me. I know I should change fuel lines, adjust timing and such but I hear "race fuel" can damage valves and valve seats. Should I just have them replaced with hardened seats or just leave it alone? Any other tips would be helpful!

 

I believe that most 350 heads made after 1976 already have hardened valve seats installed.

I could be wrong but I think that the biggest issue with racing fuel and such is what it does to the needle and seat assemblies in the carbs.

 

Just fill 'er up. It'll run just fine the way it is.

Allan

 

advancing the timing is all you really need to do - not sure how many degrees - maybe 2 degrees at a time until it pings then back it off

high octane fuel burns slower than low octane - that's why you need to advance the timing

if it is "racing fuel" or "AV gas" it may contain lead and damage your converter if you still have one on your truck

good luck

 

I cut the cat off the truck a long long time ago. So really all I should do is adjust the timing and fill'er up? Alright I can do that!