Caterpillar 5EK pros vs cons????

Just looked up the engine serial, and it was built as 375hp from factory with the aluminum pistons (as were most factory 5EK's under 435hp)
Looking over the other parts for that engine serial number to get it to 475-550hp, (or beyond) safely would require the following:
1. steel pistons (those aluminum pistons don't handle much more HP well at all)
2. dual piston oil cooling nozzles, as well as the correct oil pump bypass spring retainer or whole oil pump to match them.
2. 10r8502(58's) injectors (came with small 56 injectors, which if ,memory serves right are almost 40% smaller than the 550 injectors)
3. bigger turbo, many, many, options out there for this anymore.

edit: also to note flywheel housing is probably new because International used a different housing setup than Paccar so to use Kenworth motor mounts would require the housing to be changed.

 

Cat 3406 @ 550hp Serial#5EK87748 Vs Cat 3406 5EK98028 @ 365hp?
Can I take the 365hp and drop it in the 550hp truck and still use the 550hp Computer on it?

 

Not going to work out well at all to do that. if the 365 engine still has the original pistons in it they are aluminum crowns that like to melt down if pushed to hard, and it also has quite a bit smaller injectors in it than what the 550hp engine has. camshaft is also quite different between the two because of the injector difference.
To do it right to get to 550hp you would need to do a full rebuild with a kit for the 550hp engine with the correct pistons, piston cooling nozzles, injectors, cam, and turbo.

 

I had a felling that would be the case. 550hp motor is still in the truck and running strong, but just hit a million miles. the 365hp motor ran great, no smoke with cold start, no blow by and just pulled it out of a single axle Sterling day cab with low miles. Why such a big motor in a single axle I'm not sure, but at 5k$. i was not going to pass that up. So at least I have a very good core to go big with. Would I need to change the Crank?

 

Crank is the same between them.
The 5ek had issues with a batch of cranks but at 30 years on all the ones with issues have pretty well shown themselves already.