I have an 88 YJ 4.2L, 220,000 miles body anf frame good, Engine was knocking so pulled and got one from a junk yard from a 79 4.2L with 88,000 miles. I have been trying to put it in and I get as far as the input shaft into the pilot bushing and it will not merry up to the beel housing. It gets anout an inch away and thats it. I used the clutch and pressure plate and fly wheel from the 88 so it should slide in. Any ideas??? Thanks