Hi Tim,
I am currently building a Brookville 1930 Model A roadster with a LS6 454. It is a tight fit with NO extension of the frame. I used a Bitchin BB firewall, lowered the motor mounts, and still ran into firewall issues trying to use a HEI unit. I had to use a MSD pro billet distributor (much smaller in size) and this kept me from having to knotch the BB Bitchin firewall. If this roller motor is not enough I plan on putting a 871 blower on it. Like others have said I doubt if it will ever hook up even running my Hoosier Pro street radials. It might be fun with the 572 for sure.