Bob,

What are the cam specs for this motor? They can be approximate as I understand the sensitivities towards industry secrets.

Yeah I'll do some hunting around for the link. Well, if you want a powerful small block Sunsation, I'd give bobl a call. I'd venture to say he's the expert on the topic. He got to become quite familiar with my Dominator at his shop. He can definitely hit your goals for you if you take it to him. This isn't his first 6.2L build either.

The big lingering question I haven't got a straight answer on is the X-dimension, if it is the same as the big block boats? Bob and I suspect my drives are pretty deep, likely scrubbing off speed. My boat hooks a little TOO well coming off idle. My boat makes more power, weighs less and isn't out-running the MPH I'm reading about on here with 454s. When she's maxed out, she's flying incredibly flat...too flat.

Have you contacted Sunsation direct about the X dimension? I called a couple of weeks ago to inquire about performance mods to my specific boat. Accordingly to Joe, he said the hull is pretty much dialed in to it's max capability so bottom blue printing or x dimension changes won't add speed. I believe he said the x dimension is set a little higher than the big block versions. I tend to agree because with my boat while accelerating from idle in rougher chop or trimming before boat has a chance to level out or ride at a certain speed, my boat suffers prop blow out. Joe told me that if you want to go faster, it's going to require increased HP and propping.

I did call but I didn't get a real clear answer. I asked one of my friends with big blocks to measure so I'll have a solid answer soon.

Almost any fast boat will blow the props if you trim too soon. What makes us believe it's deep is that with three blade props it won't blow out under most circumstances. It hooks a little too well.

what is the prop shaft height

Just wondering how your builds are performing and if you tried anything new. I remember you were talking about changing props. I have the same boat as you and if finances go well, I plan on doing some small block builds.

Reds, still running about the same. I bought some labbed 23s that I haven't had a chance to run yet. Been dealing with learning this lesson: If you do a 383 build, take the time to replace all your sensors. Been replacing the junk original water pressure, temp etc.

My PM box is empty now.

Thinking about giving it a try. Anyone have any knowledge of how the TPS and IAC work with a Mercruiser ECM? Is a TPS a TPS or are there differences that will cause me issues?

Evan, I just did an engine for Simon (Simon Sez 38 Fountain). It's a 350 that we did a similar setup to yours. This was my last build before closing the shop. We went with a Holley throttle body and it came with TPS and IAC. You have to re-pin the Holley IAC to work with the MEFI, but it worked really well. Made 421 HP with a set of marine headers.

Oops, forgot you have the ECM 555. You'd have to adapt the IAC to work with the new throttle body. Don't remember how we mounted it, but it shouldn't be a big deal. TPS should be the same.