The big advantage of 55mm cam is the lube size you just cannot get that big of a lube on a standard roller. When I was going for all the pony’s biggest lube I could get was .465 lube. So with 1.8 rocker that’s 837 lift
But 55 mm with .500 lube 1.80 rocker 900 lift. Get the picture. So in other words a 55mm with .465 lube has no advantage. With only 270 seat pressure.
So I feel that’s the biggest reason behind going 55mm cam more lift.
The other thing a E-Head only has a 5.200 valve. 2.100 install hight, a high port 6.200 god only knows what a Tiger.. Visner...Warp 6 have. You can bet they need a titanium valve. A regular steel valve would be way to heavy. At least that what Dan Barton told me about a set of high Port he did and guy was having issues with valve springs, and ended up going with titanium valves.
I never believed more seat and open would be hp lost. But definitely something with 900 open pressure definitely not going to live long on street. I know we’re talking strictly strip motors.
The things they hide, the way they spin things, the excuses that they make and the things they omit.