went to pick up my belt the other day and notice something weird... they have two diffrent size belts one for cali emission( i live in new orleans) and one for i think federal emissions... whats the difference? should i take it off?

i have the cali emissions...the cali fed as well as clean vehicle all have EGR's and with that comes a vacuum pump the difference between the two is one is longer to reach the vacuum pump...attached are some pics of what it looks like and what its general location will be....i will try to take some pics of mine later....and on the technical side all four generations of the duramax engine have four belt configurations...with or without dual alternators, with or without A/C, and with or without vacuum pump.

also here is a pic of what the Egr cooler looks like this is a lly but yours will be in this exact location and again i will take a pic of mine later to show you

thanks for the help.... does this rob me of any horsepower or anything

well one thing about the egr lb7 heads is the intake ports aren't symmetrical as seen in the photo bottom head egr top head non egr...the other photos are of my vacuum pump and egr cooler so u can see their relative location, and about my vacuum pump pulley yours maybe a different size (if equipped) I'm not sure because when i replaced it my friend used the wrong set of pullers and bent the pulley (and he wonders why i like to work alone) and when i spec'd it out by part number they said that part number is to a 6.5TD but its what it came with so its what i put back on....the main reason why people block off EGR's is because as u can see in the photos a collective layer of soot sticks to everything and slowly restricts air flow including the cylinder heads which already suffer from non-symmetrical intake ports but usually only heavily modified diesels will suffer a power loss and another reason is coolant issues obviously 1300+ egt's is gonna fry the coolant eventually even just a stock 900-1100 will shorten its life span lightly...one good thing is u have EFI live if u have an EGR u can disable it through efi live