well i have an 89 s10 blazer 4x4 2door it has 193,000 miles on original motor (4.6l) and trans (4l60e).....for the past week i have had a slight nock or ping coming form the tranny but when i either brake torqued it a little or was accelerating the ping went away, but today the nock got worse....it is very bad and has a slight vibration when at 10mph or so. I believe its the torque converter but I wasn't sure and wanted some outside opinion's. And if someone could point me somewhere where i can find either a cheap replacement converter, or a complete 350 swap w/ trans that would be a much better alternative.

 

The most likely cause is a broken torque converter.

Just to clarify, you have a 4.3L and a 4L60 non-E version aka. 700R4.