8.1’s - known weak points, what’ll leave me stranded?

While I have a little time, I’m starting to put together a list of things I want to do on the 8.1’s I’ll be picking up in a couple of weeks. When I bought my boat ten years ago, I replaced virtually every bolt on part on my 454’s since everything was original. The only original part left on both engines are the coolant circulating pumps. That plan worked because I did a lot of boating and never got stranded.

I would like to do pretty much the same on these engines and have a probably once in a lifetime opportunity to start with both engines out of the boat. Basically, anything that will leave me stranded is what I’m interested in staying ahead of. If it’s just an inconvenience (and/or something that will give me warning) plus EZ replacement post install, I’m not as concerned. My list so far is: (everything is x2, both engines)

Definite:

hoses
belt/tensioner
rebuild raw water pump
elbows
plugs
wires (but might already be new)
Fluids
zincs
filters (fuel/oil)
oil/fuel lines

Likely not unless bad:

alternator
starter
heat exchanger


Unsure:

Fuel pumps - going from mechanical to electric for the first time. What’s the failure rate been on these? At 17 years, will they last forever or should I replace proactively?

ECM/Injectors - I have read about a few ECM failures, maybe bad diagnosis? What are thoughts here and I would include any sensors on this list if anyone has anything to add. Could also approach as I buy a used (ECM for example) and have onboard if failure is highly unlikely or just not worry about it.

Oil cooler - these scare me, proactively swapped them on current engines. Do the same here?

Seals - not an opportunity I had last time around. Oil pan seal is the big one, leave alone if not leaking or do it now because I have such easy access? Rear main seal on 8.1’s, how are those holding up.

* valve covers I’ll probably just do because of age
* front cover/timing seal?

Coolant Circulating pump? - lasted forever on 454’s, same here?

I’m sure I am missing some things and appreciate any feedback.

Thanks
Bob

I would change the oil coolers while you have the engines out. Mine are under the motor and the starboard side is a real bitch to get at. Fuel filters that are in the fuel cell, port side is tough to get at when in the boat.

On the fuel filter, the setup I have now has been flawless and wondering if I can keep what I have. 30 micron pre filter screen——>10 micron Racor——> carb filter.

Obviously the carb filter goes away. Do you know the micron rating of the fuel cell? Maybe I can use that as the last line of defense and taking the role of the carb filter.

thanks
Bob