dragraceguy

I am restoring a 91 Chaparral 2550 sx. the boat had 250 orig hours equipped with the 330/454/ bravo. Reading the posts i decided to do the top end and replace the heads with 71 vette heads. The compression should be about 9.2 to one. The ports are 262. I installed a crane marine cam with 529 lift. added crane gold rockers and 3/8" push rods. The motor looked almost new in the holes. Being fresh water cooled , i decided to use the performer rpm intake and a 770 holley street avenger setup for marine use. The boat weighs about 4400 lbs. it spins a 19' quicksilver prop. can I go to a 23" pitch?

BADINTN

I had a '88 2550 with the same motor that I bought with a 19" mirage prop. I installed a Crane Commander cam with .536"-.553" lift, large ovalport GM heads with 1.88"and 2.19" valves, Edelbrock Performer RPM intake, a Holley 750 DP and Stainless Marine exhaust. I ended up spinning a 23" mirage that was tweaked to about a 22.5" pitch at 4900-5000rpm. I spun an untouched 21" mirage at 5200 rpm. Over all I went from 58mph to 65mph.

HOUSTONPROP

in a 23 ACCLERATOR design would work great ,Might have to work it down in pitch but that would be a great starting point.

throttleup

Dragraceguy,

What is your WOT RPM with the Quicksilver 19P and what is the speed at WOT.

Julie

HOUSTONPROP

We can send you one to try out if you want.

One call does it all.