Classic & Vintage - dura ace 6 speed sis from '85 conversion

I have a downtube shifting sis dura ace 6 speed and want to go back to using the clicking as the friction is worn out. Will a dura ace 7 speed freewheel work with my 6 speed shifter or am I stuck with a 6 speed? What freewheels will work with the spacing of my shifter? Thanks

If the friction is "worn out" I'd say the entire shifter is shot. What do you mean by worn out?

7 speed and 8 speed are the same spacing but 6 speed is wider so a 7 speed freewheel or cassette will not work with your 6 speed shifter.

Have you tried tightening up the shifter with a straight blade screwdriver? I had a problem with the mounting screw head hanging up on the ends of the D-ring that you use to turn from friction to SIS and I had to remove the D-ring and file the ends enough that it would let the screw head seat down properly but still long enough that it would not fall out. The shifter is way more complicated than it looks but why don't you carefully dismantle and clean it and see if you can't still use it in friction mode. You can also buy a used friction shifter for a few dollars.

Actually, technically Shimano 7 & 8 speed spacing is slightly different (a fraction of a millimeter per shift) but you can generally get them to work Ok. The only spacing that is exactly the same is 5 and (shimano) 6 speed, such that you can use a 5 or 6 speed freewheel with 6 speed shifters.

Remember: some of the early DA stuff is different geometry and isn't interchangable, so be careful mixing shifters & derailers. Sheldon Brown documented that on his site, somewhere.