I know its kind of late but I thought I right a short reply.
I spent this past weekend pulling the 2GM15 out of my C&C 30 MK1.
I have purchased a 2GM20F as a replacement. The replacement is fresh water with a heat exchanger. My old engine was a salt water cooled 33 year old engine on its last leg with low compression. So here is the steps I took and some photos ,
1) First thing I did was remove the old wireing harness and install the wireing harness that came with the newer engine. I checked it over real good first. made some small repairs, but not much needed here as it was in good shape.
2) Installed the new harness but did not plug in to old engine.
3) Disconnected fuel line.
4 Disconnect the water exhaust line and strap back out of the way.
5) Disconnect the throttle and shifter cables and move out of the way.
6) Remove the raw-water intake hose.
7) break loose and remove the engine mount nuts being carefull not to disturbe the height adjustments, I want to be as close as possable eith the new engine alignement.
8) Pull the main sail and cover and stow in the foward birth.
9) You will beed 3 1X6 18" and 2 6X6 post 12" to set the engine on see the photo below
10) I then set the Main haylard to help the machanical boomvang hold the weight.
11) I purchased some new straps from Lowes with a 1800lbs rating.
12) I hung the new straps to the boom as close to centered as possable to the load. I hung the come-along
I only used 1 lifting eye as I only had one lifting point on this enngine?
The new engine has 2 which will make it easer going back in the hole.
4 points you will need to watch out for.
1) the drive coupler, I soked for 4 days with P-B Blaster and still had to cut one of the 4 bolts out with a ZIZ-Wheel. So be prepaired for rust and dont let it discurage you. Take your time.
2)The angle will be very steep on your strap the rear of the engine will come of the mounts first, this will cause the drive coupler to jam aginst the driveshaft. you will need to raise a little at the time making sure the frount is jacked up at the same time.
3) and when it comes loose it will swing foward in a hurry. I was out in front of thai as i'm sure you will be. I took some 1X6 boards and blocked it by ladder bulk head.
4) Becareful of the wood work as you can see in this photo I will have to refinish part of my teak.
All and all it was a good day. It was too hot to do this job, but I have to sail in September. I have to piush on and get it done. I am not a boat mechanic so its slower than it should getting this done... So heres the question when can I call myself a mechanic?
Any lost of luck getting your swap done if you have any questions I would be happy to share my experiances with you.