changing jets on a holly is easier on the quadrejet. if your going to some cam work or exhaust work

Not entirely. A lot can be accomplished with metering rods and hanger. Swapping them is a piece of cake.

I have a Gen V 330, my choke wire is purple with a yellow tracer on it if I recall. Not sure how different the harness between a MKIV and GenV is. I would imagine the boat had carbs with electric chokes on it originally, maybe a previous owner clipped the choke wire back at the harness...

You don't need a choke. A common mod on Holley type carbs is to mill off the choke housing for better airflow. This is from my '82 Mustang. The boat has EFI. ( I see a rotten vacuum port plug...)
http://i763.photobucket.com/albums/x...ps2c452d12.jpg

Pussed out and went with the old style choke. So basically just a $200 fully replated rebuilt carb.

FWIW, I helped a friend with his Nove that ran in a stock class so he had to run a Quadrajet, we were making over 500hp with no problem. the one issue the quad has is that the fuel resevoir area is small so they are not good if you are making lots of power and a lot of rpm for long times unless you upgrade the fuel system. we ran a bypass regulator to feed all the fuel to the carb and after that it never starved up to 7200rpm. if you know how to work on them the quad is one of the most adjustable and durable carbs out there.

+1