Fuel injected engine swap

"Hello,
I recently bought a 2

"Hello,
I recently bought a 2003 rinker rx1 with a MPI 5.0L motor. I got her at an auction knowning the block was cracked. I've swapped a 350 motor out before in another boat (carbed), and if I'm going to replace the block I'd like to step it up to a 350.

Here's the issue, with the MPI system and looking online at part numbers I found that there are different ECU's (ECM555) for the the 5.0L and the 350 motors. I'm guessing the ECU hardware is the same with just a different calibration and/or software. Maybe the 350 has different sized injectors? On GM trucks, the ECU is adaptive so if you swap the block, it will "relearn" the fuel and ignition curves.

So the end question really is, can I swap the 5.0L MPI block to a 350 block and leave the rest alone and still have the motor run right? Has anyone done this or know of someone doing this? Can I take the boat to a marina and have them reflash the ECU to the 350 calibrations?

Thanks is advance"

"great questions. Due to the v

"great questions. Due to the volumetric efficientcy differences between the 5L and the 5.7L, I suspect the adaptive learn capability of the ECU will go "out of range" (max out) - even on a GM truck. That's purely from my automotive experience on trucks and not boats. Would think a software reflash would do the trick. It would be a good question to pose to the mercruiser guys, or who ever marinized the engine."

"Have the ECU reprogrammed or

"Have the ECU reprogrammed or try to fine the correct one on E-bay. Not only are the injector parameters different, so are the IAC, timing and rev. limiter settings.

It just plain won't run right with the 5.0 ECU.

Good luck."

I have an older 1976 -77 mercr

I have an older 1976 -77 mercruiser i/o 4 cylinder engine. the outdrive from the sleeve down is new(rebuilt) Problem: I have to repalce the bellows and I am trying to remove the drive but it seems the shaft is stuck. I can rotate the entire foot 360 deg. and it has cleared the 6 bolts holding it. Every mach I have spoken with says the only way to unfreeze the shaft from the gimbal bearing is to keep applying equal pressure with crowbars on both sides. this is not working it has not moved any more. Please help