355/ 360AC Repower

[vernh59]

Hey guys, I am going to repower EZ Go when I get back and would like some advice. I currently have 2 3.8l V6 Crusaders and Velvet Drive 71C with a 2.59:1 gear reduction. :smt101 These are the original motors and they are ready to retire. I am thinking that I would replace the motors with drop in 4.3's and use the same trans. If I use a 4bbl setup I would have a pair of 210hp instead of the very tired 165's in there now.
Plan B, is a pair of 5.7's at 260-300hp but I don't know if the 71C will handle a 5.7 and I think that gear reduction would be a little much. I know some of you have this hull and 350's. What is your experience with power and fuel consumption?
Even if you don't have this hull what do you think?
I like the way these 3.8's sip on fuel even at a hull blistering 15 knots.:smt043

Thanks in advance

 

[1956olds]

Those 4.3s are gas sippers too but have as much hp as 5.0litre 305s,mabey consider feul injected 4.3s instead of carbs ,less upkeep i think.I just retired my old work van a 2000 astro with 4.3 it had 200,000 plus miles and very little maintainance requirements.

 

[Anothersearay]

my last boat - a 300 weekender - had 5.7s with borg warner velvet drives, 71c's, but the gear ratio was 1.5 to 1....

 

[Leafy Isle]

I have the 355t version of this boat and it was repowered 10 years ago with Merc 454's I think if you are going to all this work, go big. I cruise at 18 to 20 knts at 2800- 3000 rpm {load depending} these motors are loafing along at these loads. ....
ps.. borg 72C's

 

[vernh59]

I have the 355t version of this boat and it was repowered 10 years ago with Merc 454's I think if you are going to all this work, go big. I cruise at 18 to 20 knts at 2800- 3000 rpm {load depending} these motors are loafing along at these loads. ....
ps.. borg 72C's

Thats good info. I have heard that side of it before. Bigger motors don't work as hard to do the same job. Thats why I was thinking 5.7's instead of the 4.3's. She actually has a pair of 3.8's in there now. Whata difference 454's would make. :wow:
Whats your fuel burn at cruise?