engine swap on '04 sea ray 185 sport

[majmacv]

Im looking for input regarding my desire to replace a 4.3L v6 with a 420 HP small block chevy in my '04 Sea Ray 185 Sport. my questions are:

1. Will it fit (I have the optional sport interior with the rear bench seat, and there seems to be alot of room)

2. what changes to the outdrive will i need to make (Alpha I) to handle the extra power (stronger bearings, different ratios, etc.)

3. Is this boat even safe to operate at 65+ MPH? (i.e. is the overal hull design desiged for these speeds)

can i modify the transom to accomodate thru-hull exhaust?

Any input is greatly appreciated!

Andrew

[mtnrat]

I would post this under the sterndrive section, you may get a few opinions there.
I am always one for more power But,
1. dont know
2. don't know
3. That is a pile of power for that boat. I would think things may get a little squirrelly at those speeds.

[Jango]

Your 4.3 is nothing more than 3/4 of a chevy Sm Blk. The V8 will be approx 4 1/2" longer, same width with stock exhaust manifolds.

In order to get that kind of power from a small block,a High output Cam is required which results in max HP developed at Higher RPM, probably 6000 +. If the WOT engine speed is 6000+ , gear ratio need not be changed. Probably OK as is, however longevity will probably be less depending on how much the Boat is run wide open.

Depending on water conditions, 65 MPH shouldn,t be a problem

[Zackman]

Andrew, I believe the 4.3 was the largest engine offered in that boat. With the alpha drive you are limited to 300 Hp. The drive is limited in speed also, I believe 60 - 65 mph. With that drive, the 350 Mag (300 Hp) would be the biggest you could connect to the Alpha. I would save your money, and get the boat you really want and sell that SR to someone it would better suit.

[majmacv]

Thanks for the info!

Andrew

[RMSOSF]

420 HP small block???? alot of power for a mouse.