Very Disappointing Numbers
Would having the car locked make up this 30'ish HP range? Found it odd that the torque was about right, but the hp was so off, so that could explain it(?).
Once the gears/differential (3.42) gets installed I will take the car down to the track to get some time slips, but any advice or suggestions you guys have would still be greatly appreciated.
Yes, having the converter unlocked will make a big difference. Have them manually shift it into third and make sure the converter locks this time. You should definitly see in the 320-330ish range. Good luck.
Different area, weather, dynos, etc. You always pull an automatic car with the converter locked. Do it again with it locked and you will the power your are missing.

