Most Eliminators have them.Hard to find another manufacturer that has more crazy power installed in their boats.

I'm not picking on anyone, anything, just thinking if the riser was long enough to dump at the 90, reversion would be a non issue. I could be wrong.

I quoted and was refering to Fingscreenname.
(288/294, Lift .585/.610, 112 L/S cam.)

your cam is just fine.

Ooops...........didn't see that.

Being I have had the set up for 4 or 5 years now I can tell you there is no reversion issues. It has Merc 496 Aluminum manifolds and their SS risers. They are the tall of long version but that only means a 1/2" taller then the shorter ones. From there it all stays 4" and goes to the outlets in more of a pulled out "Z" pattern. In other words it don't double back on its self. All of it leans to the transom. It does have flappers on the tips. Nothing special but it works.
You can see the angle better in this picture,