I've gotten a 1956 bel air and after searing for the reason why my spidometer doesn't work and just makes noise ive found that the cable connector is to big to screw into the spidometer how can I find another cable that can screw into the spidometer or make the one I have work
At risk of sounding a bit blunt, why not just look on eBay or any classic car parts websites?
If you don't trust them for whatever reason then you could go to a local scrap yard that specialises in old stuff. I'm sure the part will likely be cross compatible to all the GM stuff of the era.
But if you really want to bodge it, Speedo cables tend to be square, just file down the sides of the thing until it fits (unless someone can explain why that won't work due to different ratios or something). Assuming that it's the cable itself that's too big and not the screw on bit.
It's not the internal square bits that's too big it's the outside bit that holds the entire cable onto the spidometer and my worry is what if the last person to work on this car also used these antique part sites so is there some sort of unit of measurement that makes sure the nut size is correct or something else
Where did the current part that is too big come from? Was it already on/with the car when you got it?
I'd honestly just punch the model and year into Google and pick the one that comes up. Speedo cables aren't expensive and given that it's probably a common parts bin part for GM they won't be had to get.
Well the part was already in the car when I got it I guess I'll try just getting a new one and if it still doesn't fit I guess Ill ether continue using my GPS speedometer or get a new speedometer