Not sure if I should ask this here or in the mechanical forum, but figured someone with old school Crusaders might know this. In the picture below, you can see the exhaust setup for my engines (new boat for me, but it hasn't arrived yet so I can't measure). You can see some leaking/rust where the manifold, collar/donut and riser are mated. Four studs go through this assembly, which I'm told is like this: manifold/gasket/donut/gasket/blockoff plate/gasket /riser then nuts to tighten at the riser end. The original Crusader parts were replaced at some point with aftermarket Barr components. The gasket parts I know, but folks at Barr were not sure about the stud length for this setup. Available studs are 4", 3" or 2 3/4". Does anyone have this set up and maybe happen to know the correct stud length?