Clunk after shifting?

[93MTXSHO]

Yesterday, I was out and about, and I made a right turn onto a pretty steep hill. I kind of pulled out in front of someone, and I was trying to get out of their way so my foot was into it pretty heavy. At about 6K I shifted from 1st to 2nd and got this horrible clunk from the passenger's side. I've noticed it before, especially when shifting from 1st to 2nd and 2nd to 3rd at high RPMs. This time, it sounded almost like I ran over something and it slapped the floorboard. I'm just wondering if anyone else has noticed this or if it points (God forbid) to a bad halfshaft. I'm pretty sure they're original at 197K, because the passenger's side still has an orange MTX sticker on it with a part number. Thanks for your thoughts.

 

[V6&V8SHO]

Get reinforced motor mounts and aluminum subframe bushings. Thats my guess.

 

[sdpatt]

Do the motor mount test. If not that, as stated above, it's probably the subframe bushings. My guess is the front motor mount, but only you can determine the true cause by inspection.

 

[93MTXSHO]

Thanks guys. I did the motor mount test and I have approximately 1.5-2 inches of lift in both 1st and reverse under a very strong load. Is that too much play? I am suspecting the front motor mount as well, because I have an 8-12 inch section of the front tank that is polished very nicely , but my hood is also adjusted down too low, so I thought that that may have been the reason for the polished intake. How much of a PITA are the motor mounts to replace? Where is the cheapest place to get decent ones, and what are the part numbers? Thanks so much.