also in middle of 1970 swinger slant 6 to 440 swap. having major problem with oil pan idler arm interference. first pan i bought that was supposed to work was a night mare of bfh clearancing and grinding of k frame lip just to get motor down in the hole. realized it was never going to let me turn to the right so unless i only wanted to make left turns it had to come back out. found a pan on 440 source that supposed to be a repro of c body pan with the notch built in for idler arm cleance so put it on and it is nowhere near correct either. i tried to clearance it with hammer and not working. either i am doing something wrong or my 70 was put together differently or idler and pittman arms are too short or bent or something. even raisng the motor with 3/8 spacers isnt going to clear. i am wondering if idler arms could be heated and bent down jjust enough to clear or if that is impossible. only other solution i guess is fabbing my own pan notch which i can do but i dont understanc why nobody else seems to have this problem i'm having