You want a set of harden marine logs. There going to be cheaper then a set of water injected headers and definitely cheaper then a set of water jacketed headers. The trick is finding them for a small block seeing how most JetBoats run big blocks. I have a set of BBC logs with the snails that I would sell.
But on a budget that's going to be your best bet and easy to setup.
Just my 2 cents. Good luck👍
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