OP, trust us when we say a dyno tune is worth it. I know you are worried about cost but in the end, if you go your route, you will be spending more money than what a dyno costs....
Trust us all...we have been there, we have done that....we have the T-shirts and we sell the T-Shirts. At this point and where you are with your car, it's time to open the wallet.
Cheap, fast, reliable...pick two of those.
Matthew 26:52-54 / Go Pack Go!
1987 Mustang GT Hatchback - 2V Mod Swap In The Works
1997 Lincoln Town Car, PI Intake/Cams, Sofa-On-Wheels, "Fat Tony" we call it
2001 GT Convertible - D1SC / Geared / Cammed / 440wh 400wt - TOTALED 2/2019