273 piston options

Interesting that you mention E85. There isn’t much close to me, but I’ve been looking into it. What’s really strange is how viscous it is. It’s almost oily. I have no idea what’s in it (yet) that makes it so oily and viscous, but I do know it changes the tune up. By a quite a bit.
If you elect to run e85 on a carbureted application, you’re better off ordering a drum of e98 ethanol and blending your own fuel from there with non ethanol premium pump. e85 at the pump varies from 50% to 83% depending on the seasonal blend.
Calculate Ethanol % of Mixture