I worked for the Zimmerman brothers at their speed shop in Greensburg,In. for the last 2 yrs before they retired. I was fortunate enough to have Gary build a BBC and a SBC for me before they closed the shop. These are mild street type builds for roots style blowers and can run 87 octane pump gas. Built with all quality stuff, double groove crank nose, etc.We were figuring longevity in street hot rods rather than brute horsepower. They are 8.0 comp and I was going to run about 6lbs of boost. The BBC dynos at 567hp before boost. Needless to say I have slowed way down since those days and hence the sale. I have specs available, just PM me for info. They have never been fired although I do turn them over regularly manually. The blowers do NOT go with them. (I do still have the itch somewhat.)