Mercruiser repower from 3.0LX to 4.3L

[reidsworks]

Can anyone tell me if a 4.3 V6 L will bolt up to the Alpha outdrive? I have a 1995 Mercruiser 3.0 LX Alpha 1 in a 1995 Mariah Talari. The water jacket on the block has cracked and I am considering repower with the V6. Gear ratios for 3.0 LX listed at 1.92:1 and the 4.3 listed at 1.84:1. Doesn't look like a huge difference but local shop says I'd have to change alpha outdrive too.
Cost for long block 4.3 is actually a few hundred less than the 3.0.

thanks

 

[Bondo]

Re: Mercruiser repower from 3.0LX to 4.3L

Cost for long block 4.3 is actually a few hundred less than the 3.0.

Ayuh,........

But you Need a Complete Bobtail Engine......
Along with Alot of Other Parts to make it Work......

You'll be up into the Expensive, had to find Prop pitches without a Gear Ratio Change......

 

[Bt Doctur]

Re: Mercruiser repower from 3.0LX to 4.3L

Bolt up,Yes. exaust systems need changing, need to construct 2 front motor mounts on the stringers at the proper height,may need to widen the engine cover, and change the gear ratio in the upper unit.

 

[reidsworks]

Re: Mercruiser repower from 3.0LX to 4.3L

Thanks Bt Doctur. Motor mounts and exhaust shouldn't be a problem, Mostly concerned about changing out drive gearing. There is such a small difference in ratio out of the two engines I would think the Alpha should work as is.
Can you be more specific?
Engine cover not an issue as it is a euro style bowrider. Lots of room under the sundeck. The 4.3 was an option I passed on when the boat was new due to cost.

 

[Don S]

Re: Mercruiser repower from 3.0LX to 4.3L

The gear ratio is different to keep the prop in the most effecient range. If Merc could have just used a different prop to get the best results, they would have.

 

[4winnsskipper]

Re: Mercruiser repower from 3.0LX to 4.3L

The 4.3 was an option I passed on when the boat was new due to cost.

now the swap will cost double.