Carriage lock bolt on Hendey lathe help

I have a few Hendey lathes, great machines I like them. But the what I think stupid placement of the carriage lock bolt is wrong! Over the years I had just about every US made lathe of the top of the line Brands. I have also a P&W and L&S and the carriage lock bolt is in the front not in the back like all my Hendeys which requires reaching over or under work being turned. In most cases this is not an issue but as the lathes get larger the distance gets longer. I'm sure that over the years what ever style head on the bolt was used has been replaced. My 24" Hendey of 1956 vintage had a 1/2"-13 hex head bolt. I didn't measure but I'm guessing the distance from the front of the carriage to the rear is more that 2 feet. To make a slight modification I ordered 12" of 1-3/4" of either 4140 or 4340 can't remember which but size 1-7/16 nor 1-5/8" was available. The nuts on the tail stock are 1-7/16, I have a box wrench 1-7/16" and 1-5/8" on the other end. I milled the top of the 1-3/4" hex bar to 1-5/8" X 1-1/4" long and use the 1-5/8" side of that long box wrench. The other side was faced and tapped 1/2"-13 X 2" deep. I replaced the bolt with a 1/2"-13 extra high strength stud that extends out the extends out the end of the clamp enough to put a high strength nut plus a jam nut to stop the stud from turning and done to lessen the stress on the threads in the clamp. When putting on the above mentioned loooong nut I well coated the threads with copper never seize. Works OK.
My question is that it seems to require more torque that I'm thing it should require to lock the carriage, quite a bit more that the P&W or L&S to do the same thing yet I'm not using a wrench about 2' long. I'm thinking of putting a thrust bearing on that long nut but wonder if it would also help vibration to loosen the clamping force. Any suggestions?