305/350 efi compatibility questions

[Littlejohn85]

Evidently I did not winterize my boat- and now I have a cracked block. Current motor is a 1997 mercruiser 5.0 efi. The price for a long block is basically the same for either a 5.0 or 5.7, so I might as well upgrade for some extra ponies. I'm sure everything is comparable with the exception of the fuel injection PCM. Are they different for 5.0 & 5.7? If so, can the pcm/ecu be re flashed? Any suggestions for a company that can handle a marine re flash?

 

[Fun Times]

Hi there, welcome to iboats

Some engine models use the same ECM for both models and some don't. Do you by chance have the original engine serial number in order to take a look without guessing?

If it's needed then OBD Diagnostics should be able to re-flash your old ECM http://mefiburn.com/

 

[Littlejohn85]

I don't have the serial # off hand, and didn't see a sticker having one. Is it stamped on engine somewhere?
OBD diagnostics has different several part #s for 305/350 applications.

 

[Fun Times]

You're correct, looking around your engine model years, there seems to be a difference in ECM's. Try giving the company above a call to see if they can help.

To find the Mercruiser serial number, look either on top of the engine stickers or just above the engine starter like these,