I R&R the timing chain and gear set it up like the manual says crank gear at 12 o'clock and the time gear at 6 o'clock turned engine till intake valve closed and mark on damper was at TDC put distributor in pointing at number 1. Set timing at 6 degrees advance 32 total. Engine starts right up but idles very rough. Checked firing order truck seems to run good above idle but very rough at idle. Don't know why. Any suggestions for the problem would be a great help truck is 1995 K2500