I recently did this exact conversion for a friend. First thing I did was remove the Tyco trucks with their truck mounted "talgo" couplers. This leaves a gapping hole in the frame bolster. I filled this hole with the appropriate diameter styrene rode and glued it into place. I cut the rod off flush with the existing bolster. Next, after the glue had dried, I drilled a #50 hole in the center of the rod. I then tapped it using a #2/56 tap. I used a #2/56 screw to mount a pair of Proto2000 70 ton freight trucks.
To add couplers, I installed Kadee #148 whisker spring couplers in the provided Kadee coupler box to the car's underframe. To mount the coupler/box to the frame, I simply positioned the box on the car's underframe and marked the center hole location of the coupler box. I then drilled a #50 hole into the underframe and threaded it with a tap. Once installed, the coupler height was at perfect height when checked with a Kadee height gauge.
The replacement trucks, couplers, and mounting screws cost approximately $10. But, that is a small price to pay because the sentimental value to the person is priceless.
Good luck,
Tom
To add couplers, I installed Kadee #148 whisker spring couplers in the provided Kadee coupler box to the car's underframe. To mount the coupler/box to the frame, I simply positioned the box on the car's underframe and marked the center hole location of the coupler box. I then drilled a #50 hole into the underframe and threaded it with a tap. Once installed, the coupler height was at perfect height when checked with a Kadee height gauge.
The replacement trucks, couplers, and mounting screws cost approximately $10. But, that is a small price to pay because the sentimental value to the person is priceless.
Good luck,
Tom