well my 95 t/a has a new 383 with around 600 miles on motor. has scat forged rods and crank, trw pistons, 4 bolt main, le3 heads, comp r lifters, comp cams 468 cam, crane fireball, msd coil and wires, electric w/pump, l/t's, 3" o/r y-pipe, gmmg catback, 2400 stall. well i drove it easily for miles then the opti's rotor button shattered. well i replaced it took it out for a drive and decided to get on it. im running motorsport z06 wheels 18 rear 17 front. it wouldnt keep traction. well on the wat up my road when i did it and let off the gas it stalled out. i started it back up it stalled then it started up and would stay running if i was on the gas but would make a knocking clanging noise all the time no matter what, even whit the coil unpluggedjust spinning over. its extremmely loud. pulled valve covers and everything looks good, pulled the oil pan and bearings looked good but changed them anyways. any ideas? oil pressure is good while on the gas dont know about at idle because it wont. the nite before when running with new opti i reved it several times but didnt start doing it until i got on it driving. its driving me nutts because i have spent so much on it for it to be doing this.

 

I would start by taking off the timing cover to check the well being of your cam/crank/timing set

 

i have checked it and compression everything looks food. also the timing set it new also from gm performance

 

oh the problem with the opti was it was the factory original with 112k and my roommate stepped on it and i didnt relize until i took if then he told me

 

What kind of "clank/knock" is it? Deep? Metallic? Does the motor shake when you hear it?

 

it sounds metal.its louder under the car. and as far as shaking i havent tried starting it since i replaced bearings. but it would only stay running if on the gas.

 

Is it a light "tink" or a hammering sound as if you were pounding a mini sledge against the block?

 

i think i found the problem. i went to turn the flywheel and it turns a .5-1" before the rotating assembly does.

it sounds like a sledge hitting under the car

 

now i have to figure out about a flywheel. what would you recommend?

 

I'd think the flywheel would've caused all kinds of vibration. It's quite possible the flywheel bolts backed out causing what you have now. The flywheel is most likely done.

 

if i turn it real quick back and forth it sounds like what i was hearing just not as loud