Mercruiser 3.7 Exhaust Riser

[ImperialV184]

I replaced my riser this weekend after 3 years, the bolts came out a lot easer than I thought. and they looked pretty corroded. I had no coolant leaks into the oil and it did not look like the gasket was failing. My Manual does not call out the torque for the riser, I have looked everywhere. It only lists exhaust manifold torque at 25 Foot Pounds. I noticed an older post on this site that said 25 foot pounds for the manifold and 30 foot pounds for the riser. I could not tell if this was for the older cast iron manifold or the newer aluminum manifold. I have the aluminum manifold. Any help on torque values would be appreciated. 30 Foot pounds seams low given that it is a 7/16 bolt vs the 3/8 bolt for the manifold. Also I used Perfect seal. Was this a good idea?