DA and temp are big factors.
A lot of people don't get that. "Why did you spend all that money to just run 12s? I can do 13.3 where I live." Then you look up their track and it's DA is regularly -600 feet while mine's 5,500+... Then when you adjust your time or their time for altitude they tell you you're bench racing. LOL
Keep in mind many of the serious drag guys convert to E85 or have M1 Injection.
Very true but the LNF's fuel system is limited in it's overhead to spray the additional volume of fuel E85 needs. Last I looked into it with the LNF (years ago) a lot of guys were doing a E45 blend and/or running additional port injectors to get the volume then letting the stock Direct Injectors handle the fine tuning of the mixture.
I'm also looking at other runs by gxps or redlines with trifecta's. I'm trying to figure out whether 102.4 or whatever is a typical speed or if it should be faster. I've seen some runs that are in the 107 range! I know every track is different but I'm trying to figure out if that let up of pull feel I had at the 5300rpm range in third is normal of if I have something slightly off somewhere...
Your DA is pretty good...humidity probably killed you some, hence the higher than actual elevation...
I would guess your trap speed will go DOWN if you get a sub 2.0 launch the Grand Prixs (being FWD) considered a 2.0 launch on street tires really good and I hit a 1.997 60' on them ONCE (great track prep) so with those old Goodyears, I bet you may have a 1.8 in there with some decent tires. General rule of thumb is 0.2ths in the 1/4 for every 0.1 in the 60'. So that 13.6 could be a 13.0-1 with a good launch on sticky tires and nothing else. What were your pressures? Fronts should be as high as the tire allows and the rears definitely in the mid to high 20s.
As for your trap, keep in mind that the more you spin, the lower your et and the higher your trap...generally.