SBC install-weird noise when on/off throttle

[megaladon6]

just installed an SBC stage 2 daily in my MK4 jetta. it drives great and is quieter over all than before. but i have a weird noise when i come on/off the throttle sharply. it's kind of a "tchunk." if i ease on/off it doesn't happen. and it doesn't seem to happen from a stop. if i had to make a WAG right now, i'd say gear backlash. but...
other than that, i am really happy with the install. the pedal is MUCH lighter and the car feels much better. granted, my old DMF was almost certainly shot. we had to hammer the inner part into place to line up the bolt hols-i assume this is abnormal?
thanks

 

[megaladon6]

just a clarification. this is not chatter, idle or otherwise. it's a one time noise when i hit or release the throttle. i have tried doing a search and everything i find is an idle chatter.

 

[eb2143]

Motor mount issue? Remember to tighten them all?

 

[Trawlercap]

I had a strange noise that turned out to be one of the dog bone bolts was rubbing against my panzer plate. Any bump, or acceleration, or quick stop made the plate act like a drum and really send out some strange noises! Was intermittent. Easy to see with the plate removed, you could see the rub spot.

 

[megaladon6]

also replaced the motor mounts with the 60d ones (though i will double check the dogbone, it's the only one that i didn't tighten/watch it get tightened). the noise definitely sounds like it's from the area of the transmission--though i realize that it's almost impossible to properly localize while driving.
the noise does not occur on bumps, hard starts/stops (at least not yet, it's only had the one drive...) it's not loud, i really don't notice it with the stereo on, and when it's at volume? HA!