I am considering a boat with just over 900 hours, it has twin 350 Mags, and I am worried about if they will need a rebuild any time soon.... Some of my friends have said you can run 350's up past 1500 or 1700 hours and they will be fine... well I don't know about that, -thanks

What type of boat and how do you plan to run it? A compression and leakdown test will help determine the health of the motors. At 900 hours, I would think it is due for a valve job at a minimum. If you plan to run the boat hard, I would go ahead and pull the motors and freshen them. If you are just going to cruise around, then pending decent results from a mechanical inspection you could run them until the performance starts to drop off. I had a friend that ran a 5.0L motor to over 1,200 hours before he sold the boat. Motor still ran like a top and used no oil but had lost some power and lost a couple hundred RPM at WOT.

I'de run it and worry about it later, being from ohio myself i realize just how short summers are for a project like pulling motors and rebuilds. I would save it for a winter project.

It all depends on how it was run. I know of a ton of wake board/ ski boats that have over 2000 hrs on smallblocks. If it's a go fast, then that may be a different story.


Darrell.