1st and reverse clunk sound
 

Its me again, car is EJ1 Civic with straight H22A swap, M2F4 trans.

Now that I have my starter issue resolved I want to figure out this clunk sound. The sound isn't when I actually shift into 1st or R but as soon as torque is applied to the wheels from a stop. I also hear it sometimes when i let off the throttle after hard acceleration. It isnt all the time, if Im gentle engaging into 1 or R I don't hear it. It does seem to be coming from the driver (left) side and I can also feel it in my feet through the pedals. Also at the same time I started hearing this I hear a high pitched squeak/whistley kind of noise that is RPM dependant while accelerating at or above about half throttle, maybe it is unrelated but the timing suggests that it is.

My first thought was a motor mount, bracket, or something in the suspension. So I just finished thoroughly looking at every large bolt in my front suspension and also all of the mounts and brackets, the axle bracket and the steering rack. Nothing is loose anywhere and everything looks normal. The car shifts perfectly fine, runs and sounds ok besides these 2 noises.

I did read somewhere that the "diff pin" can make a clunk sound like I am hearing. I did spin the wheels/axles while I was under the car but didn't hear anything unusual. Im not sure how to verify this possible "diff pin" problem. As far as the squeek noise I was thinking maybe clutch/flywheel? I did replace both of these 2 years ago (oem) and 1 year ago I did the timing belt/water pump/ oil seal (all oem) maintenance and also a full tune up (plugs, wires, cap, rotor, and internal coil) Besides this I havent touched anything else engine/transwise in over 5 years.

I know this is quite long and rambling like my posts always are, I just try to give as much info as possible. Any ideas or suggestions anyone?