Oil filter differences

My girlfriend's 02 883 Sporty and my 98 Fatboy both use the same Amsoil oil filters. The 135. My buddy was in a jam so I helped him out with a new rear tire and an oil change. After changing his oil and installing a 135 filter that I had on hand I find out today that his 06 XL 1200c needs an Amsoil 134 filter. Are there that much technical differences between the two or do we really need to get the proper one. Amsoil tech says they are quite different. Any opinions? Thanks.

I would listern to the amsoil guy, I dont think I would chance it over a 15 dollar filter, probably different micron rating or something like that , not enough flow and you could starve the system of oil, to much flow and you could not filter out enough impurities, Todd

Other than length, the main difference is that the EaOM135 doesn’t have an anti drain back valve so it should not be mounted horizontal or upside down where the oil can drain out when it engine is shut off.
This is the email reply from Amsoil. So if the oil path on an Evo engine is from bag to motor to filter to bag, the anti drain back valve is not really an issue, right? I mean the 02 883 and the 98 Fatboy are both Evos and use the 135 filter. My buds 06 XL1200 should be fine. Please correct me if I'm off track. Thanks

P.S. I talked to the Amsoil tech on phone yesterday and got the tech email today. Feel better about my screw up now.