I have a 1996 Formula 419 sr1 with triple 502 mag mpi. (not a stepped hull) I run 25 pitch 3 blade mirage props for a top speed of 75 mph at 5100 rpm. I am putting in 3 prochargers M1sc with 5% boost. My question is what speed can i expect out of this set up and which is the best possible prop and pitch for top end performance.
An advice would be helpfull. Thank you.

Expect 4-6 MPH Top Speed ( not gain) with blown engines

These old engines will have to be rebuilt prior to supercharging

The 419 SR 1 likes 4 or 5 blade props in combination with Imco
3 `rise extension Boxes and some more HP

Motors have 150 hrs on them. Done head gaskets ect. Not planning on stripping the motors down as i have 180 psi com. Had the boat for a few years dont get out much in it so motors are good to go.
485 hp on last rebuild 6 years ago. I should be seeing 700 hp with procharging and 5 or 6 pounds boast i hope. I was thinking of 4 blade hydro 29 pitch props to start off. Maybe to much maybe not have to wait till spring to test. Snow is starting to fall up here.

Just be gentle on your drives, Bravos I assume.

419 SR1

started as TWIN engine boat
twin 465 - 55 MPH
twin 465 with Pro Charger 70 PPH
lasted 10 hours only
Triple 496 HO `s 72 MPH
Triple 496 HO `s upgraded to 525 HP each 79,8 MPH GPS
Imco Extension Boxes 3 `rise
Bravo 1 lab finished props 30

Boat planes on any 2 of 3 engines with the 30 `props

Go with Imco SCX drives if you exceed 600 HP
just my 2 cent

wow never knew these 419 were offered as twins. You could put some big power with staggered setup. Why did the orginal motors fail with prochargers.