engine chatters when not at idle..

[YoungMopar]

so i rebuilt my small block over the last couple months..what i did was strip the engine down to the block, did not remove the crank, just everything else. installed new rings, rod bearings, double roller timing chain, jegs performance cam (.449) oversized valves in heads, dual plain highrise intake manifold. 650 cfm carb. new gaskets and seals. installed motor had running for 3 hours, drove for 30 minutes to gas station and back, everything was perfect! time for main voyage home, over an hour drive....30 minutes into it, it sounded like something was bouncing of my firewall. pulled over and the engine has a chattering noise which seams like its coming from behind the timeing cover....people are telling me its could be the converter....however i di change the conver, i put a big block flex plate on it with a converter from a 440 satellite...(ran grat for 3+ hours, shifted great)...then i started noticing that the oil pressure was dropping slightly, (plenty of oil, no leaks, not burning it) but its also the electrical sending unit (we all know how accurate those can be on the factory gauges...)so needless to say i have a bitchin motor, looks amazing, sound amazing, but under load it "chatters", i wont call it a knock cause it sounds like something rotating thats just loose, now everything internally was bolted back to factory torque specifications. two main caps were takin off to replace the main seals...thinking its the front main bearing cap...but would think that it would be a different tone. recently purchased a stethoscope so i can kinda pinpoint where the sound is....now i was informed that if i was a rod bearing that if you take the spark plug off while at the rpm where it makes the noise, that the noise would stop..doesnt seem logical but i did it anyway. and now change on all 8....can spin engine with a breaker bar with no problems...any ideas!?!?!? feel free to even text me 603-988-9688 names iggy

 

[krowbar]

Do you have an electric or mechanical fuel pump?

 

[YoungMopar]

mechanical...does sound like its coming from that area...was thinking harmonic balancer or fuel pump, so i was going to replace the harmonic balancer and switch to an electric fuel pump and hope for the best

 

[YoungMopar]

not the fuel pump. thinking input shaft bearing is causing the torque converter to bounce of the bellhousing, which makes sense cause i found marks below and above the flywheel