'99 21z with 5.7l what ratio Alpha leg?
 

Hi,

Another quick question if I may please, seeing as you all seem so friendly and knowledgable :D

This 216z I am getting is a bit of a project boat (potential money pit I know, done a few before, but anyway....), and the leg is missing (long story, dont ask :shakehead: ), so I was wondering what ratio Alpha leg others are running in this size mariah with the 5.7 (260hp version), and what pitch prop? Not looking for max top speed, just to be accelerate to ski and frugal cruising.

Thanks! Anthony

I'm running an alpha 1 (gen 2) drive with 1.50 ratio and a 13.75x21p stainless prop on my 5.7L. I get good holeshot and top out around 53 mph. I can stay on plane down to about 20 mph.

Yours is a little heavier and carrys 50% more fuel, but I don't know if that will factor into the drive ratio at all.

I'm also running an Alpha 1 (gen 2) drive with 1.5 ratio. My prop is 14.25X21P stainless and I get decent holeshot with about 57-58 MPH top end. I'm still considering a smaller diameter (same pitch) because my RPM's max at about 4400.

I could easily be wrong, but I thought all Alpha 1's are 1.5 ratio. There may be a "high altitude" version or something, but all of them I've seen or heard about are 1.5.

Hi indykoch,

Here's a little info I borrowed from the internet about Alpha gear ratios...

"Mercruiser made the following gear ratio changes in an effort to develop stronger gear combinations:

What was a 1.50:1 thru 1995, in 1996 changed over to a 1.47:1
What was a 1.65:1 thru 1995, in 1996 changed over to a 1.62:1
What was a 1.84:1 thru 1995, in 1996 changed over to a 1.81:1
What was a 1.98:1 thru 1995, in 1996 changed over to a 1.94:1

In 1998 Mercruiser introduced the 2.0:1 gear ratio which has since replaced the 1.94:1"

WetWilly

Thanks WW. I never knew they had all these choices! I've been in the midwest most of my life, and I believe most boats around here are the 1.5 or 1.47 since there's no mountain ranges, tides, polar ice caps, 5' rollers, rogue waves... what would all the corn grow in???

I guess it makes sense to offer all these ratios. For some reason, I had it in my mind that you needed Bravo 1, 2, or 3's to get the different choices. Nice info to know - thanks!