sxfreak2002

i have been chasing my tail all year and nothing has worked . so im asking for any suggestions. i have a 4link dragster with a 572bbc and im shifting at 7400 and after the shift im dropping off to about 6200 and crossing the finishline at 6000. my sixty foot times have dropped.from 115 to 128. and my 1/8 mile has dropped to a 540. at 128.was running 770s at 176. 1/4 and 490s 1/8. last year and the only thing i have changed is the rods went to grp .car started off at 8.00 at 168. i have changed everything i can think of. checked all the wires,new plugs wires cap rotor coil . changed the converter.new tires the motor was freshened at the first of the year.did a leakdown ,compression check checked the springs.the cam .i have a retard box on it and it is grounded and a zero chip so not sure if it can still cause a problem.i am lost what else can there be the motor seems to run fine .holding9 pounds fuel at 6200 on the converter. changed carbs. if anyone has a clue what else it could be please let me know im thinking that it may be the tranny. got it going to the shop tomorow. but is there anything in a glide that can put that much load on the motor?