Just got an 84 300cd-

It shifts hard into first and second, close together. I fiddled with the EGR and vacuum hoses and have it working a little better, with mixed results.

The transmission seems to work irregularly. Today after first messing with the EGR, I felt like I got more torque but the transmission wasn't shifting as long as I pressed the throttle. I also started to notice the "thunk" in the rear end when approaching stop.

I blocked off the EGR at the valve using the soda can method. Then i disconnect all the hoses from the black box, plugged up the orifices and turned the three way connectors around the VCV into two-ways. I think I got all of this right.

It still shifts hard, but at around 3,000RPM, is this correct?

I've tested vacuum using this chart:
http://www.peterschmidtransmission.com/vacuum/1977_1985/617_95/1981_1984.jpg

I get over 20psi at idle at all points except for at the VCV itself, which I understand isn't supposed to hold vacuum but leak it. At the VCV I get 10psi.

Vacuum is strong at point "b"- to the transmission. Does this mean my transmission modulator is okay?

What else should I check? Help would be greatly appreciated.