What all has to be done to do this?

Remove all three sets of outdrives and motors, remove all of the trip pumps and k-planes, new transom (remove and replace the wood inside the motor compartment, patch the holes on the outside), new controls (unless you want a set of dead controls), and have someone that knows what they're doing re-rig the boat with new locations for the two new motors, re-install the K-planes and pumps, re-install the motors and drives, and enjoy.

I may have left something out, but I'm sure someone will pick up the slack if I did...

It's a lot of work, but it's not mind-blowing or considered a crazy thing to do. It's definitely something that I would consider doing if I was interested in a boat, it was set up as triples, and I wanted it set up with twins.

Could the sale of the removed engine and drive cover the cost to convert and re-rig the hull ?
ed

I should have been more detailed, basically what changes need to be made to the stringers, mounting points for engine mounts?

If its a good 1000 to 1250 with #6 I will do the labor you pay for parts and supplies.

Interceptor yes... Obviously pending what motor drive combo it is...

What year 42 and what engines are in there now?

No engines no drives, but the bravo housings are there & it's a 95

Do you want to ultimately make it a stock twin setup, or are you looking to make it staggard? And do you plan on keeping the drives bravo style or stepping up to something that requires transmissions?

must be talking about the ebay 42 in CA, been for sale for quite awhile, looks like it would make a nice boat
http://cgi.ebay.com/ebaymotors/1995-...item3cb441595a