jfranks

I found a good deal on a 20' Baja with a 4.3 V6. I was wondering if a V8 swap is possible using the same drive. Any info would be great! Thanks

Baja_man

What size V-8...5.0 or 5.7 or bigger? More than likely your alpha drive is a 1.81:1 or possibly a 1.65:1 and with the larger engine a lower gear ratio change may be necessary. This would be the most costly part. Other than some wiring changes, it shouldn't be a huge deal.

jfranks

Thanks for the info. What kind of power will that drive handle?

picklenjim

Actually going to a larger engine would require a higher gear ratio change to like 1.50:1. Your gear ratio should be on a plate on the side of the drive. Of course you would also have to have room in the engine compartment.

If it's an Alpha probably 300hp safely.

Irishtornado

A Alpha Gen II will handle easily up to 330hp. It's not the drive but the gear ratio because your going from a V6 to a V8 you'll have more HP and thus with the higher gear ratio be spinning to high of RPM's. Check the drive for the ratio it should be on the side of it usually the right side of the drive on the upper. If you have a 1.50 ratio you'll be fine it'll just be a matter of swapping the motors.

Baja_man

So going from 1.81:1 to a 1.5:1 is going higher???

Baja_man

Usually the 4.3's have the higher ratio, but certainly check. If you are just going with a 5.0 you could use a 1.65:1 also. I think that is what comes stock on most newer 20 OL's.

jfranks

I'm going to see the boat this weekend. I'll have more info on it then. Thanks for everybody's help!

wtfo

When I first did a similar swap a few years ago, a local marine engine builder told me with a wink to try the 1.84 gear ratio after i did the swap - he was right, the boat is faster with a 1.84 and propped accordingly...

Use what you have first.

FIXX

iTrader: (2)

A friend of mine had one,,4.3 with a 1.65 drive...check the stringers real good,,bring a socket set and see if the motor mount bolts are tight,,they rot really bad..wouldnt hurt to knock on the stringers also..