Took the 68 Barracuda to the track today. Something isnt right. The basics of the combo are a 360, Edelbrock RPM 65cc heads (OOTB), 11.2:1, 292/509 cam, Weiand X-celerator, 750DP, Hooker 1 5/8" headers, 2 1/2" exhaust, Holley Blue pump (still running 5/16" line), 4-speed, 4.10 SG on 275/60-15DR's. The car was hooking fine launching at 4800 rpm. Ill list the details of the timeslip below...

60'---1.841
330'---5.374
1/8---8.408
1/8 MPH---82.98
1000'---10.912
1000' MPH---95.00
1/4 ET---13.125
1/4 MPH---106.03

That was the best run of the day. I made a total of 6 passes and each one got slower and slower.
The only thing I changed was I went from a Action Plus to the X-celerator manifold, and installed a new timing set. It sounds like a stupid question, but could I have installed the timing set a tooth off or something or could it be running out of fuel on the top end because of the 5/16" line? It has 3-5in of vacuum at 900-1000rpm. It just seems lazy. It wont even break the tires loose in first gear on the street. Anyone have any ideas? I figured this thing would run way better than what it did.