gkull
Well-known member
The rule on cam duration is:   The higher the CFM of head flow the less duration is required to make the equivalent power.   It is all about filling the cylinders 
So I have always used big head CFM with big solid roller lobes using steep ramps and lots of lift. Then i retain streetability with less duration.
434 ci Motown SB Endurance road racing lobes 248/250 110 .685/.714 I originally built it with an off the shelf Comp Cams SR extreme 242/248 110 and it just didn't have enough bark for me
				
			So I have always used big head CFM with big solid roller lobes using steep ramps and lots of lift. Then i retain streetability with less duration.
434 ci Motown SB Endurance road racing lobes 248/250 110 .685/.714 I originally built it with an off the shelf Comp Cams SR extreme 242/248 110 and it just didn't have enough bark for me