No reason to derail this thread I will start another

Btw, there`s no 11 plate, it`s 8, 13 or 15

And their all interchangeable with a different cover, correct? Or do they make spacers so that the same cover can be used?

They make a special cover for the 13 and 15 plate coolers.

My bad, I thought it was 8,11,13......either way, I have the 8 or 13 NOT the 15, but the important part was I use BOTH bell housing coolers for the engine, combined with 210deg oil thermostats.

http://www.hardin-marine.com/c-730-f...l-coolers.aspx

I think thats how the 750 supercat mercury engines were setup, and the 900sc mercury engines.

Makes sense since Unleashed had Mercury 750 Supercats and we copied the plumbing when building the new engines, but REPLACED ALL the lines and oil coolers.

The aftermarket bellhousings have an additional water line , that runs external, from bottom of stb side, to port side, for additional water flow. The old merc bellhousings, have a fairly small water passage internally. I wanna say eddie young adds the external crossover line to the merc housings. More water flow makes the coolers more efficient.

Are the Merc housings notorious for being a restriction and is there a noticeable difference with the external line? Seems like Merc would have that worked out...