rebulid, replace, crate new or rebuilt

[mikes]

the 350 mag mpi vortec is getting tired, has anyone rebuilt theirs, or does everyone get a replacement? if replaced, do I go with a new crate, or rebuilt, if either where best to look?

by the way, it is not easy to tell from serial numbers the exact engine, it always seems to lead back to the 315 hp model. many crate long blocks are noted to have less hp even though the compression ratio is the same, valve sizes are same, the only other factor could be the cam,

is the mercruiser cam incredibly unique or can a similar comp cam do the job?

any thoughts are appreciated, I plan on starting this as soon as the water gets colder

thanks

[chpthril]

If you are an experienced engine builder, then you can easily rebuild it for less then a reman. Unless you have the place to do it, tools and knowledge to tackle the task, you will be better off getting a reman. Even if you are paying a shop to to do the work, just get a reman. Most come with a warranty. All the shop has to do is pull your old engine out, swap over the accessories that dont come with the reman block, and drop it back in. The labor and part will be far less then the labor to have them pull and rebuild.

Although the cam will look the same to the naked eye, the cam for a boat will be spec'd for the marine application, just as a can for a work truck will be different for the same 5.7 block thats going in a Camaro.

[boatwakes]

Mikes, where's your location? If you can afford it, complete turn key engine, usually around $8500 from merc. Rebuild from a shop that knows marine engines, rebuild the injectors, new transmission cooler, new drive plate, new exhaust, water and fuel pump runs close to the same and the shop should offer at least a year warranty. The true advantage to drop in turn key is it's only about a 4 hour job from start to finish. Waiting for the rebuild or remand long block takes a while so we try to replace with drop ins as often as we can.

[boatwakes]

And do not buy any engine or long block from first mate marine, we had one go south for a customer after 15 hours because they polished the valve stems down and used cheap K guide inserts instead of using the correct guides and valves. It hung an exhaust valve and then suck water into the motor. Come to find out it's happened to many other people too and they are not good at honoring their warranty. So if you buy a long block it behooves you to purchase a genuine mercruiser remanufactured long block and not one that says it will replace a mercruiser engine.

[mikes]

thanks, I appreciate the input, i am trying not to be penny wise and pound foolish.

If I go with the merc long block, what items should I replace, besides hoses, and things that Tige located beneath the engine?