I just now saw your post and for me the answer is no! Mostly because I mix 5 gals of 110 Leaded with my 91 octane ALL Gasoline. My 110 octane has been $8.75 gal for several years now and the 91 octane here in Tulsa usually sells between $2.75 and $3.50 gal.
My original 427 Iron block side oiler with solid lifters really likes leaded gasoline. Smells good too!
Leaded gas solves a lot of problems.
Clois