This may help????:dknow
Slash Out Dyna Shorty Dual Slip-On Mufflers
Part # Description Price
80492-07 MOUNTING TYPE: Slip-On
DESCRIPTION: FITS: '07 Dyna® Models (except '07 FXDSE2) and '08-'09 49-state Dyna Models (except FXDF, FXDSE2 and FXDFSE)., MAKE: Harley-Davidson®, STYLE: Slash Out, NOTE: Installation requires separate purchase of Muffler Clamps P/N 65296-95A (Qty. 2). - Dyna Shorty Dual Slip-On Mufflers
It shows the same number for the earlier bikes too 80678-08 when you use the link I posted above and enter the 07'-08 bikes.
Here's the results I got looking for an 07 bike...
Screamin Pipes | Official Harley-Davidson Online Store
For what it's worth, usually the 07 or 08 on the end denotes the first model year for that part.Likewise if it said 10 at the end that would be for a 2010 bike as the first year for that part meaning it has been changed in some way or upgraded.
Let us know how they work out.