for intake you can use kanaflex and your choice of filter, must get a 4" adapter if youre going with that size. its the cheapest intake that I know off. I bought a used riva intake that costed me about the same.
some people have gutted their waterbox to gain some performance and added a free flowing pipe. seems to work fine for some and its not that expensive. again I found a riva box from someone for good price.
FizzleXS sells a nice external intercooler that it would be very good for you since you dont have that. or just get a stock one of someones RXPX model for cheaper price.
trim the reverse bucket, some say it helps some say it doenst, what ta hell it was free and few minutes of my time. if you look at your reverse bucket you will see that the edge in middle kinda gets in the way of nozzle. there is a perfect curve on it that you follow and trim, looks like factory if your good with dremel.
fill the ride plate holes, not sure if that really works or not some swear they gained a bit top end. if you look at your ride plate and where the bolts are, there are basily holes that supposedly drag the boat. who knows if thats true or not I doubt it but again its cheap. there should be a DIY somewhere online how to do it, some rope and whatever filler people use to smooth it out.
groco strainer to go with intercooler, filters coolant so your IC stays clean and lasts longer. they are cheap online
also riva makes a catch can, some have made their own and didnt cost them a whole lot. again I bought a used one online that didnt costed me much.
you can add skegs to your ride plate, should make the boat handle a bit better. I have them for sale new not used as I bought a riva plate and wont be needing them
you can remove that filter element out of your intake manifold and that should give you supposedly a 1lbs of boost. you have to remove the intake manifold and go thru throttle body, kinda pain to do it but its cheaper that riva kit that drills it from other side.
im sure im missing something
