Make sure front and rear chains are not to the end of their self tentioning, may have to remove half links. Make sure tention is proper for both chains. Make sure slats have not wore enough to lose their aggresiveness, replace slats or chain or I have even ground leading edge square again. Do you have the factory knotched type slats or something differentIJ Just so you know it is often the back chain that causes problems with the front. I highly recommend shock kit. False floor would be fine but that would get plenty spendy. look on bottom of square tube just ahead of front feed drive sprockets and if some arrow shaped chunks of iron are welded on I would remove and grind surface smooth. Now I would look at area between the front feed drive sprockets and that square tube. The sprocket teeth should clear square tube by no more than an inch. R40-50's and I believe early R42-52's had more like 3" clearance so material would pool in there and cause us plenty of trouble with front feed in some conditions. Earlier N's, larger machines, and later machines all had closer clearance to square tube and gave use much less trouble. We fixed ours by picking up some 2"x4" tubing and welding to back side of square tubing which closed up that area enough to eliminate problem. We just held in place and welded along top where you can get at it. Use as long of piece as you can get in there and center it the best you can. Good luck.