Try 23 pitch 3 blade mirage props.I think you will see a few mph diff.

I'm running 23 pitch 3 blade mirage props and get to 68-69 easy , get it trimmed right and worked it up to 70.5 gps
What brand are the 4 blade props? was thinking about getting some for better take off and mid range but don't know now if it kills your top end that much

low to mid 60 mph....thats crazy I run 70-71. with stock everything. just make sure you run your tabs at around 1 OR THE BOAT WILL RUN SLOWWW. I spentsome time on this....(a sub and some beer) anything past one will cause it to loose speed. Ican only guess its because it keepstoo much of the boat in the water

I am running power tech OFS props 22 pitch. The boat comes out of the hole very smooth and quick. 4800 rpms top end no tabs applied. tried trimming the drives every where... 63mph on gps

Mine will do 73-74 depending on cooler and fuel, last gps was 73.2 with 3 people 3/4 fuel and coolers and crap. mirage 27 pitch 3 blades. It sucks coming out of the hole but one it's up it's great, oh thats at 5000 rpms.

Thanks for the feed back maybe when i get some money i will try some other props.

Mufflers
 

Is anyone using mufflers on thier boat? Will this have an affect on top speed?

Not on a couple of small blocks. They are easy to remove though. For a couple of hundred bucks you can get better sound if you remove them.

Those 4 blades are killing you.

looking at some on e-bay right now... thanks for the input.
Do you think it would turn 25 pitch?
What RPM's are you getting on your boats?

I have done a ton of research. Assuming 1.5 drives and 350's, 23 Mirage +'s are the props.

I have 377 MPI (6.2's), with 1.65 drives. I run 26" Bravo 1's to the mid 60's. The factory gave me 23 M+'s but I was on the limiter with them because of the drive ratio.