Help, Car real sluggish

ok. I have a 91 GSX. I just got done rebuilding this engine. Punched .020 over, new rebuild kit, 3 angle valve job, small 16g turbo, datalogger, S-AFC, and 550cc injectors. I also put in a shift kit, and new clutches myself. With the 550cc's in it would take off the line pretty quick untill about 4,000 rpm, then it would start to shake, almost like fuel cut, but I would look at the datalogger and it would show that it was getting plunty of fuel. That was pushin 20psi. I put the heaviest spring in the transmission and it would shift real good between gears! If i didn't drill out the holes that are suposed to be drilled out in the valve body, will this play any part of the problem.
Thanks for reading,
Scott

no, maybe, but make the car shake? unlikly. does that happen in every gear around 4000? or just first? if its just 1st, then its more then likly somthing in your tranny. if its all the time, post a 3rd gear WOT 3-7k log for us to check out.
Scott =)