What is the main difference?

Compression ratio?

Would i benefit from them, or should i stay away?

I can get a set for free...

 

allot of people put marines in when rebuilding, it does drop the compression a little but allows for some more timing due to the wider bowl. if you can ge them free, i say do it.

 

i put them in my puller this past winter. i was already at 26 degs. i need to bump it up a little more but i still felt a little power increase.

 

ok, i have them laying around but i've already built my motor...

i will definately have to put them in the next time i pull the motor or get an extra 5.9 to build on the stand..

 

Don't know if it matters but this guy I know said the gen motors were the highest hp motors Cummins made in the B series. I believe the motor tag on one my other friend acquired said 230HP@2600rpm. maybe meaningless what do I know IMANUBE.

 

The marine are higher 300-370 hp