stren drives

[manitou1968]

I am repowering a Cruisers rogue 2870 1991, the original plant was twin 350 ( same rotation Mercruisers 260 HP with Alpha 1 Gen 1 drives 1.5 ratio. Boating has changed in the last fifteen years, now Cruisers's 28ft comes with twin V-6's . I have already purchased the marine 350's . Is the Alpha 1 still the best drive for me and how much of a problem will I create for myself if I convert to the 1.32 ratio (the big block ratio) to achieve lower RPM at cruising speed. The boat weight is 7800 lbs. second revision on the weight
Thanks for yor help

[Jango]

The 1.32 ratio should not be a problem as long as you stay with the same or less pitch propellers. Your boat appears lite enough for Dual 350,s with the 1.32 gears.
Jango

[manitou1968]

Thank you Jango, sorry I messed up onthe weight (7800 lbs)the other option available on the boat in 1991 is the single 454 with alpha 1 .I have also found out that the twin 350 alpha1 set-up was very common to much bigger boats up to 33 ft.

[Jango]

You should still be OK with the 1.32 gears. If necessary,Less prop pitch will take care of any "Lugging" problems. You're only talking about a 12% gear change.
You can also achieve "lower cruise RPM" by merely increasing prop pitch with the present 1.5 ratio. This could be a very viable option especially if your "new" 350,s have more HP (Torque).
Jango