DiverDAD!..
I've dove wet, then dry, and now wet again. I have a pretty good grasp on wetsuits and weighting.
First off, you are using a s/s backplate, is that correct?
and you are not that big a guy at 185 lbs.
The whole secret to weighting with either a wetsuit or drysuit revolves around your final stop at 15 feet after your full length dive.
The ultimate weighting is when you can hold a perfect stop at 15 feet with no air in your wing and/or drysuit (if you are using one. In your case you're not) and control your buoyancy with your breathing alone.
Don't try to weight yourself so heavy that you sink feet first as soon as you dump the air out of your wing. Weight yourself so that after you dump all the air out of your cell you can still float on the surface. You might, at that point, need to flip over head first and kick down a ways to about 10 feet before you get enough pressure on yourself that you can break neutral. Your breathing has a lot to do with it too. Breath out and mostly empty your lungs as you're trying to get down from the surface. After all, you're not freediving so there's no reason the hold a full lung of air.
After you get a few good deep dives on that suit it should find it's place and you will know how to weight it.
Just to give you an idea:
I have 2 wetsuits. Both of them are custom made. Both of them are 2 piece john/jacket beavertail style with attached hoods, so both of them have doubled up material on the torso.
One of my suits is a 7mm (a fat 1/4", - so a little more than 1/2 on my torso),. With that suit I use a 4.4 lb s/s plate, a steel 120 tank and my weightbelt is set at 22 lbs. I am 6'-4" tall and weigh about 225 lbs. I can hold a perfect stop at 15 feet with this setup.
I have another suit which is 1/2" thick (12.5 mm.- almost 1'' of rubber on my torso!!!) I use this suit for temps below 45 degrees. With the same tank and plate, I use a 38 lb weightbelt and can hold a perfect stop at 15 feet at the end of the dive with the wing empty and fine tuning my buoyancy with breath control alone.
Get some good deep dives on the suit, break it in, weight yourself so you have all aircells empty at 15 feet and can sit there, then get back to us.
Good luck
Eric