Hi there, I have tried looking all over on this forum and corvette forum for answer to my problem with no luck. I have an 85 s10 with a 383 stroker in it. It has about 10,000 miles on it since build. I recently put on a new dynomax muffler and as soon as I finished putting it on, I parked the truck and let it sit. The next day I went out to drive and as soon as the water temp gets to 130-150* I can hear a tick. I went throught the exhaust and sealed up all joints with muffler mender, tightened the clamps, and checked all over for leaks. The sound was still there. It is not very noticiable from the top of the motor but you can hear it much better under the truck. It increases with engine rpm but only when warm-hot. I took off the fly wheel dustcover and check the flywheel for slop and it looked good, no missing bolts or anything. The flywheel came new with the stroker kit any way. I went through all the rocker arms and they are quiet and pumping oil well. I have normal oil pressure all the time too. I was convinced it was a lifter. I pulled the intake yesterday and all lifters look to be good. I pushed with all my weight on the rocker arm trying to get on to collapse and they were all strong. I check hedder gaskets and they are good. The speed of the tick is 1/2 engine RMP. I listend with hose and it sound like not around the oil pan but right above it in the motor and it louder in the passenger side of the motor. I have no power loss or anything. Could I have cracked a weld on the headers or where the collector pipe is welded to the headers? I dont know what to do now. Thanks in advance.