transmission from first to second hitting rev limiter at full throttle after fluid and filter change.

I have a 2005 dodge ram Daytona Edition with some minor mods. I changed the tranny fluid the other day at 105,000 miles. I used ATF+4 and changed both filters. Now when I slowly take off and let it shift into second I can hammer down on it which drops it back down into first, but now its hitting the rev limiter before it allows it to shift into second. It used to bark the tires at second gear now it pauses and then slowly shifts. This Daytona will run a 9.27 in an 8th mile @ 391 hp at the rear wheels. Is it possible the previous fluid was synthetic. I do have a Bullydog Gt engine tuner installed, True dual flomaster 40 series exhaust, hedman headers, underdrive pulleys , CAI, 85mm throttle body.