W2 heads and E85

What do you do with valve seats?
Lead substitute doesn't mix with E85.
Do you have to install hardened seats? If so, do the heads become more prone to cracking?

what is the intended purpose of the engine, street only,street and strip or strip only, not knowing this but maybe someone can answer, are the seats induction hardened? that may make a difference.

Street and strip

Nobody has done this?
How about with pump gas?

Any early heads ( usually pre 1971 ) will have valve recession with todays fuels. How severe it is depends upon valve spring pressures and usage. Induction hardening seat areas on older heads can be very tricky and often not successful ( cracks). Having stellite seats installed is the answer - also a good way to save older heads that have had the snot beat out of them.