Hi everyone I'm hoping you can help with solving this mystery.. Now a little back story.. 2 years ago i had my 5.0 rebuilt by a local builder for my 88 speed density mustang. He bored the engine over and added hyereutic pistons and increased the compression a little. At the time i also added cobra intake and new 19lb accel injectors (busted one of the stock ones taking it out of the lower intake). After installing the engine and going through the break in period i noticed it just didn't seem to have what it used too. Without any load the engine idles and rev's amazing. Under load its a different story. Basically if you pull away and accelerate lightly the engine runs up through the revs great. If you launch hard it pulls like crazy till around 2800- 3000 rpms and then she sort of bogs out... keep pushing it and she will eventually walk her way through it. Since then i have been chasing this issue and have not been able to solve it. List of mods at the time of the rebuild.. Cobra Intake Adjustable fpr (set at 39) 190 lph fuel pump Fuel filter Electric Fan Underdrive pulleys Ford Racing wire Autolite 25 plugs (gapped at .052) SS Shorty Headers Stock Cam (trying to keep the computer happy) List of mods since and parts replaced (trying to find/fix the issue) 70mm throttle body AFR 1472 heads (suspected the stock e7 head's springs were weak, good excuse to upgrade anyway ) 1.7 rr MSD Blaster TFI Coil MSD Dizzy Ford racing wires (3rd set) Autolite 3924 (gapped at .040) FPR has been set to 42 New MAP sensor New EGR New EGR Solenoid New TAB and TAD solenoids New TPS New ACT I have run the codes the a hundred times over the last 2 years and up until 2 weeks ago it has always been 11. The last little bit its now showing codes 94 and 44. I have tested the vacuum diverters and everything seems to be working. I had a local ford mechanic do the head install and set up the tune. He played with the timing for hrs adjusting it in increments. The last time he had it advance to 24. He stated at the time that it was acting like it wanted more but he was not willing to go there.. The car now runs great except for the hesitation problem. I'm running out of ideas any suggestions?? Sorry for the long post..