Car won't run past 60mph

I road tested today and confirmed that I get third gear. Yes it's late in the rpm range but do have it. I have to let off the throttle and then it shifts. I will slowly dial back the lokar that will provide less pressure until I get it in desired rpm shift point. By adjusting the low-reverse band to spec I get reverse now as soon as i hit the gas. Before I had to Rev up a little. However, I still can't go much faster than 75mph confirmed by GPS. I still hear surging when I get on it. I can still burn the tires but no top end what so ever. Like some agreed earlier it must be the convertor. When I adjusted the line pressure it helped with the 1-2 shift it's nice and crisp. Drove it around about 30 minutes. Besides me having to still adjust for the third gear rpm range and it not wanting wind out the gears. It runs good, it likes to cruise at 50mph at about 3000 RPM. Motor sounds good Tran seems fine. It really just feels like it's ran out of gear by 70-75MPH.