Extremely Hard WOT Shift 1-2

[MileHigh04SCREW]

Good morning from Colorado!

My Gryphon arrived yesterday afternoon with custom 87-tow and custom 91-perf. Very very excited. I have a 2004 FX4 SuperCrew with a SIDO Magnaflow cat-back, Volant CAI, 325-60-18 Nittos and a fresh full synthetic Mobile 1 Oil and Tranny Fluid flush.

I loaded Level 3 (91 perf) and at wide open throttle, I have a violent shift between 1 and 2. Really, really violent. Scary.

Has anyone had any issues like this before? 2-3 shifts fine, 3-4 shifts fine. Normal driving shifts great. Just when I floor it, the transmission slams into second gear.

Thanks for any help! I will probably give Bill a call later this afternoon. Cheers!