I did this recently, I put a qt in the converter. Intended for 1.5-2 qts, but got sidetracked
......Spin the converter after you've added fluid.
Grease where it meets the crank. Grease the seal, if it's not already. ATF on the shaft...Basically grease or use ATF on all contact points converter to shaft and converter to crank.
Slide the converter in nicely, maybe a jiggle, and spin. You should feel/hear 2-3 clicks. When it's in right you'll know it. It must spin freely, and you should be unable to fit your fingers between the housing and the converter from underneath. If it's installed right the converter nuts should be 8/10"-1" from the front of the housing. My stick said 8/10"ish, don't remember. Mine is a 400TH, but I think the others are the same or close. You can help lock the converter in place with some rags, though you wouldn't want to leave one behind (yikes).
When it comes time to bolt the converter onto the flex plate, the nuts on the converter should be approx. 1/8" from the plate. Spin it, should be nice and free. Then pull the converter to the plate, check spin and then bolt it on. 1-2 drops blue thread locker on the threads. You might look up the torque, I set mine at 40 ft. lbs (GR 5 flange bolts).
Look up info. on how to top off the trans. fluid. I have a total of 5 qts. in my transmission and converter. My 400 takes 9.5-11 qts., the rest comes during first start up.
Incidentally, a helping hand is nice. Pull your spark plugs and have someone work the crank so you can bolt it to the plate. From the front the crank spins clockwise. I installed two bolts on the damper to spin the crank with a bar. Should spin fairly easily.