I have an 86 s10, with a 2.5 in it, the original engine was blown, so the guy i bought this truck off of put a brand new 2.5 in it. Well, it only has about 30,000 on it, and for some reason it locked up one day last week, after rattling really bad ( sounded like broken throwout bearing). went to shift from 2nd to 3ed, (5 speed), and when i went to let out on the clutch, the engine stopped and locked up... I took the tranny out and put on new throwout bearing and clutch. still wouldnt turn over, i drained the oil and no metal shavings came out, and all the pushrods are still in good shape and are all there. Any ideas? ive asked a few people about it because they knew quite a bit about engines, and they dont know exactly what it could be, ive been told bent crank, main bearings went out, connecting rod(s) broke, or something in cylinder wedged against piston, any suggestion would be of help, I am thinking about new 2.5, or just going to a 350 with 350 turbo tranny for sale from a friend.