I have a pair of '05 525's that have an in line fuel filter. The number on the filter is 35-807174. I can't find them anywhere. Two Merc dealers told me the new number is 35-864572. That filter does not fit. The female thread section is too long and the ferrel nut bottoms out before it tightens up the fuel line.

HELP!

Type in your part number in this link. 807174T
http://www.mercruiserparts.com/partsByNumber.asp

I believe who ever is looking up the part number is not adding the (T) at the end because when I looked up part number 807174 it came up as customer can not buy this part, But it is Active within the mercruiser parts system, Now if I put the (T) at the end it comes up as an available part and the factory has over 22 in stock.

The part you got does it have a T at the end?

There is no "T" marked on the filter itself, but I will try that part number. How did you know to add the "T to the part number?

I got these from nuwavemarine on E-Bay
Mercruiser Mercury Fuel Filter 35-864572T they fit on my 500efi

Your Mercrusier dealers should have known to look up "your engine" instead of going off of the number on the filter as a back up plan.