I don't think Mopower had shorties. I know he talked about it, but I don't think he ever bought them. So when are you going to replace the 311. I was boatless for one summer when I was 17, that summer sucked.

BOY - Those engines dressed up nicely. Lookin good.

Thanks- I'm hoping that I can get the hydraulics plumbed this weekend and possibly get the motors dropped in. How is your project coming along?

I got all of the EFI parts and pieces. I got all of the sensors installed and the computer mounted. Now all I have to do is the wiring. I got the injectors and fuel rails installed tonight after I drilled and tapped one of the fuel rails for the fuel pressure sensor.
Need to order a bunch of fuel line fittings.
Anyone have a Summit coupon there not using???

So here is the update from the weekend. I finally got one of the engines in, I really needed to get one in, so I could see how the geometry changed with the new engines. While the blocks are the same dimensions, the dart heads have the exhaust ports raised .30 inches. Not only does that move the exhaust up, it also moves the exhaust out. Not a big deal if you're using short tails; however, I'm running dry pipes that go through the transom. So with all that said, I need to pull the swim platform next week and and modify the existing cut outs.

I also removed the old cable steering and everything associated with it at the helm. Needless to say, the hole in the dash for the old helm is ever so slightly to big for the new hydraulic helm. So I will need to plug, fill and re-drill that as well.

All in all, things are moving along, but as expected, nothing goes 100% smoothly.

I am not sure I would remove the platform and recut holes in the transom.
I had the same issue going from steel stock heads to aluminum d shape exhaust ports.
Pipes moved 0.50 up and outboard from the original holes.
I cut the tails to fit. May have been more expensive on the initial change.
But cutting, filling the transom is never easy or cheap. Plus the strength of the transom will not be compromised.
If something doesn't get done exactly right, the transom is too important structurally to risk it.
Plus the standoffs will add to the loads to the transom.

JMHO

Sounds like you started one of my projects.

Thanks for the advice, but look at it this way. A triple engine boat transom is same thickness, yet has 3 drives, and six exhaust holes, and a lot more stress. They don't have any issues with structural integrity. Boats with big power are running up to 5" exhaust pipes, no issues there. I seriously doubt that enlarging the hole a .25" to allow the pipes to fit, will reduce the structural integrity of the transom any measurable amount. Now, If my transom develops issues, you can certainly say- I told you so.

Ouch. I stand corrected.
You are 100% spot on.
0.250 isn't enough to make any difference.
I was mentally going with a 2" move.
Plus you are going away from the drive cutout.
Good call on your part.
On my trip engine swap, I had plenty of room to adjust for head differences.
I had new headers made to fit.
🤑

Any updates ??