The 460 Marine engines came with a front sump Cobra Jet oil pan. They hold 6 quarts and have an integral windage tray that also helps keep oil around the pickup. For a front sump pan, they do pretty well in a jet boat...remember, they had to keep oil around the pickup in a car with tires on asphalt/doing hard acceleration (much more g-force than a jet boat at launch).
So, whether or not you "need" a 10-quart pan depends on how you run your boat. That being said, a full-length rear sump large capacity pan certainly wouldn't hurt and would be a very smart move if you run your boat hard. When your pan comes off for pan gasket replacement, what you need to do is at least confirm that you have a CJ oil pan that has the windage tray. If you have a bone stock passenger car pan (no tray), then replace it with a rear sump jet boat pan for sure.
When changing from a front sump to rear sump oil pan, you need the pickup that goes with that specific pan and you usually have to also change from a front sump-style oil pump (M84B) to a rear sump style oil pump (M84D). Some jet boat pan manufacturers offer two different pickup tubes for a given jet boat pan, one for each type of pump..so you need to know which pump you have if you keep your existing pump and order only a pan & pickup.
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