Stage 6 heads don't get a lot of respect but a good Friend of mine has gone lots of 9.70's at Keystone with them in his beautiful street legal duster. He did his own porting work

1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time