I have a formula 242. The PO had a bow tie mk iv 502 installed that pushes the boat to 62mph at 5200 rpm on gps with a 23p mirage plus. The internals are unknown. It has the stock 454 merc intake manifold and a edelbrock 750 cfm carb. When getting up on plane it seems to lean out and run like crap on the primaries. I have to ease into the secondaries to get past the lean condition and plane out.

Would you just try bumping the primary jets up in the existing carb or try to find a hp 500 intake/ carb combo?

If I did upgrade would there possibly be a noticeable performance increase?

Rejet.

Unless your budget dictates otherwise.....

A properly tuned carb can make the difference between useable, and winter.....or mid season rebuild.

....and to answer the last question.....

Depends on how you tune the carb.......