Leaded/Unleaded?

[tknuss]

My grandfather recently passed. He left me his 1973 Centurion Convertible. It needs extensive body work and interior work, but runs fairly well. I have a question regarding the fuel that the car accepts. While he was alive my grandfather always indicated the car took Leaded fuel and he used Lead additive anytime he filled it up; however, in the manual that I found in the glove compartment the last page states "use a high-octane unleaded fuel". Can someone please let me know what to use and if it's possible to change over the car from leaded to unleaded? THANKS!!!

[Robroy]

I have a Centurion 73 myself with a 455 that I bought recently.
I've been told it should be unleaded high-octane fuel.

Hopefully some other members on the board can confirm this, or give some other information.

[tknuss]

Thanks... yes, it's a 455 as well. I appreciate the quick response and wait to hear from some others as well!

[Smartin]

Use the lowest octane you can without allowing the engine to ping/detonate. If the engine continues to ping on the highest octane street fuel you can get, then you have a tuning problem...most likely timing issue.