[CriticalMass]

No, not a turnkey. ERA #164. He documented just about everything related to the car (all his cars really) so I have a complete history of changes he made, even down to what dates he rotated the driver and passenger side seats to avoid uneven wear....of course though, the information I need is in another log book that I can't find.

Knowing him its documented somewhere, but I've looked extensively and haven't found what I need.

I would just hate to have to tear the engine apart to check compression ratios when I know the car is tuned perfectly...for an unknown fuel mixture. Especially since I've never done it before. I have general engine maintenance skills and am technically inclined. I have the ability to tear it down and get the compression ratio, but nothing ever goes as planned. I don't trust that I have enough experience with this engine to troubleshoot problems that might arise during the tear down and rebuild.

I'll probably just put 1/16th of a tank of something around 100 octane in it and run it. Then I'll start cutting the 100 octane with 93. If I don't experience problems along the way I'll just settle on running it with 93 octane w/additives (whether that be racing fuel or octane booster). If I do encounter problems I'll at least know the ballpark I'm in.

But just to be sure, nobody thinks I need to add lead substitute?

Thanks for the replies.