The B4 & B44 shocks are the same, just the B44 has longer shafts in the front.
Are the bodies clean, nothing at all where the o-rings fit?
Also are you using new or old plastic parts?
New parts may need to be trimmed to fit.
Have a read of this:
http://users.telenet.be/elvo/12/8/1.html
MiCk B. :-)