How do you change the rev limit of 4600 on a 1998 carbureted 454?

What igntion do you have??? TB IV or TB V????

In your other post, you are running 12* base and 36* full advance timing on a blower engine. IMO, that is too much timing for most blower engines. The 7.4 is also a poor candidate for supercharging. It has cast pistons, crank and small rods.

i dont know if v or vi but it has a module and a knock sensor on the side of the distributor. Ive had the supercharger on it since 1998 but havent been working it that hard. maybe thats why its still together. better just leave it alone! not

It's hard to say why it's lasting this long but i am glad to here it is for you, Just be careful with it and it sounds like you might be ok Because I'm guessing the timing numbers you are running is working good for how you operate your boat, If you do leave it alone then make sure keep on boating the same way you have been all these years, Because knock on wood if you change your ways now and start trying to race every boat in sight then your engine may want to change it's ways also if you know what I mean. Normal blower engines like to run with the timing set up a round 28 to maybe 30 degrees as a norm that is what most of experienced guys like to run at. Good luck with it

If its not broke, don't fix it.

ill back the timing down a little and sacrifice a few horsepower to keep the engine alive.

thanks

I think the rev limit was 4800 or 4850.
Either way, you'd need a modual from a 454mag or a new ignition system to raise it.