What could this be, valves?

[Julioluko]

Ok guys i have problem, a new one. I just dropped a 6bolt in my 2G andi have this loud squeak from the engine, i think its the engine, pretty sure but what could it be, valves? also i had something in that cylider before i started it up. that little tid bit of info could be helpfull. what do you think?

[helliviknow]

im and idiot with engines but id check the small stuff first.. belt tensions, pulley bearings and what not.. or maybe theres just a mouse living in there somewere