Why are some lb7's harder to prime than others
 

Is paying the extra money for 5" exhaust over 4" worth it?

5" is a pain in the neck to fit and rather big.. lol but hey if you want a deeper louder truck the fives the way to go but the 4" will be easier to work on.

Do you have to have a 4" down pipe on duramaxs?
Is a full 4" system sufficient with high hp?

yes with 3" your egts more then likely be high if your going high hp.. you probably have to find a 4" downpipe and custom bracket it yourself though. Xtreme Diesel Peformance should have one. If not try Pinnicle Performance Exhaust. :tu:

You could try matching title to content of thread :s:

lol and that too

Exactly,

what's up with that!