yes! That particular side I can’t get corrected I always have a bit of a pinch in it! Drives me insane I suppose it could be an issue as well?

Center rise manifolds are like cylinder heads, 1 casting for both sides, hence the water inlets on front and back of the exhaust and spark plugs pointing front on 1 side and back on the other. Manifolds can be plumbed in the front, the rear or middle-- y ing or t ing off to the inlets

How you have it plumbed isn't wrong and most likely not the cause, it just seems to me that distribution block is for feeding mercury manifolds and risers.

my opinion, aftermarket manifolds for hp gains and look as well therefore less hoses equals cleaner look but more parts have to be bought to get it.

Dry to tail pipes or not ? Flappers ?

Are you running any external or internal back wash flappers? When you back down is it possible you are getting backwash into the exhaust?

yep dry to the tail wirth a flapper

How about sealant on intake manifold/head bolts? Have you figured out if your engines require any?

If one engines oil had much more water in it than the other, I would somewhat think exhaust is not the issue, especially if exhaust was all pressure checked.

Maybe I missed something but how long was it ran on the dyno and did you dump the oil afterwards?

we ran them each for 1.5hr hell maybe 2


I didn’t dump the oil but I pulled the oil filter and clean as could be.

Have you pulled spark plugs? If exhaust related I would think would see signs of water on the plugs. If no signs of water then I would think the issue is more internal related