Hey everybody,

I just bought a Baja Islander for "pennies" from a guy, it was too good a deal to pass up. The only down fall is that it has a 4.3 V-6 Thunderbolt in it. The boat needs a new y-pipe gasket, I have read these can be a pain in the a** and i would need to pull the motor anyway. i figured since I have to get the motor pulled why not put a small block in it. Any suggestions on which engine to go with? I would like to stick with a chevy block. Maybe a 5.3?? THe boat is carborated now, should i stick with a carborated engine, or go to EFI?

the boat did 55 or so (if the speedo is right) i would like to get maybe 70 mph out of it.....

It has an Alpha 1


any helpful comments regarding would be appreciated.

a 4.3 is nothing more than a 5.7 with two cylinder sawed off.
Easiest swap would be a carbed 350.
Your not gonna hit 70mph unless you modify the V8 though.
The V6 already makes decent power (220hp?)
So youll probably need to double that to pick up 15mph.
I dont know that hull would be safe at that power/speed.
If it was me I would put thru hull exhaust ,
lab the prop to pick up a few extra mph
and enjoy it as it is.

You're not going to like the handling of an Islander at a true 70 MPH. That's a family boat hull and they get stupid real quick with too much power.

If the engine is in good shape put it back in, run the chit out of it and put the $$$ saved in the fuel tank. I'd rather run 70 on a jetski than in a "family" boat with an alpha and no hydraulic steering.

Thanks for the replys guys.

So it sounds like 70 isnt gonna be happening. If i were to drop a 5.7 (350) in it, do you guys think it would be worth the time and money? I sold my Outlaw, so i would like to get a little speed back. I did some research last night and I believe i have a 175-200 HP engine, i believe the 350's have 280 HP or so...? Thoughts?

Or should i maybe just throw on an aftermarket carb and call it good. It looks like the boat has a "quadrajunk" on it.

Thanks for your tme everybody.

Quadrajet is fine for what you have, you will not pick up any power by changing it.

Depending on the 350 you buy it can be 260hp, 300hp, and I have seen some reman companies offering them in 320 and 340 hp.

One way or another you will need a different upper unit for your alpha as the V6 and V8 ratios are different so you don't hurt them and don't have to go crazy with props....

It takes (on an average) 20 horsepower to add 1 m.p.h. I would talk to one of the supporting prop vendors, lab the prop and leave it at that. I've gone the soup-up route on a twin engine boat in the past. I spent a ton of money and got not 1 cent more when I sold the boat, including the fact that I had to buy a second set of larger stainless props for the increased horsepower. Also my drive maintenance doubled.

My kids have really gotten onto the water sports the past two years (tubing, etc.)

As far as gasoline, I SURE MISS MY V-6!

I had a Sea Ray with the 4.3, and we could go all weekend on a tank.

Yup,, my nieghbor has a small 18ft Scarab with the V6, I borrowed it a few times last year
when my boat was down, rides like a floor jack but runs an honest 55mph on gps and would run around all day on 5gal of gas.. Sometimes it makes me wonder if i am doing it wrong!