I have a 99 312 fastech with what the salesman said were labed 26p props. I get good perfomance out of them, but I bump the rev limiters at 5100 rpms and about 74mph. would I be better off with 28p props and would that knock my top speed down.

they would probably bring the speed up a little and lower the rpms off the rev limiter.

Yes, trying the the 28 stock props will help to deternine where you ultimately need to be.

You must have the 454 MPI (310HP version). I'm pretty sure that boat came with stock 28's from the factory....and Formula tends to do their homework before putting a boat out there (I had a 98 312 with 502 mags and 30 pitch 4 blade bravos)

They are 385's with 1.5 brovo's and these are not the stock prop's, someone messed with it before I bought it. I would assume that 28' would work better. Now do I buy lab finish or stock?

I have a set of labbed 28'sfor sale.

Are you sure they are 1.5 bravos.....every 312 I've ever seen came with 1.65's. (Drives could have been switched). Best thing to do is get a set of "perfect/new" props and start running/ testing her. I'm doing that now with new motors and using a trued set of props will help you figure out where you need to go.

Thanks for everyones help I will have to find a place that will let me try diferent props, and there is only one local prop shop in my area. I am afriad if I keep bumping the rev limits That I will damage something.

I may get a hold of gsmith9898 if I find 28's are a good fit.