After pb blasting..heating and drilling out rusted bolts I have one left to fix. The front end top shackle spring pin with grease fitting on passenger side wouldn't budge with an easy out and heat. I decided to drill out and hopefully run thread chaser thru. I took pin into couple places to get correct thread and size. They were not much help and told me must be an odd size thread. Has anybody had to run a thread chaser thru the pressed in threads for top shackle spring pin? I did a search and only saw that 3/8ths 24 was used for the grease zerk but saw nothing what would be used for chasing spring pin out. Could some on chime in on maybe where to find proper size as I don't see it covered in my assembly manual..just replacement part number for whole frame bracket. Auto zone guess was 3/4 10. I think thread size is wrong. Any ideas ? Thanks in advance luv this site. Jeff