We have two D8 583 sidebooms S/N 16A1- and are having a hard time finding track pins #4B6620 and bushings #4B6714, I have even called Cats main office in Peoria with no luck finding any. After these machines came out they did offer a kit to change them over to the newer rails although I have been unable to find any of these kits also. Any help with finding these would be greatly appreciated.

I ran those parts on Machinerytrader parts chase ,and found serval pins around the country Florin Tractor has quanty 6 of 4B6620 pins in stock came up empty on any 4B6714 bushings in the system.Wonder if a standard D8,46A bushing could be machined to match the 4B6714 I am thinking of a 5M2037 master bushing or a 8M 2619 standard track bushing used in a 46A D8
Don't know how many you need ,but check Machinerytrader parts search for the list I found

I am looking for a full set and have even went as far as calling a sideboom dealer in Canada who knows just about every boom that was built with no luck, what would be nice is one of the conversion kits that Cat came out with to change these over to the new style rails. I am starting to think that I might have to find a D8H and convert everything over to it, I have looked at having pins and bushing made but in the end it would still be a small pin rail and we have these machines set up to lift 220,000 lbs. and use them often for Railroad work.

If your rollers have some wear you could re-rim to a late 9" pitch Euclid 82-30 sprocket rim and run D8H-K track

I have been looking at the 9" pitch conversion and need to find the sprockets to fit our machine, can they be pulled off a later machine or do I need to cut ours down and put on a new ring?

I have found track chains, pins and bushings for these machines and want to thank everyone for your help.

Glad you got what you need. Post some photos of the change out and the machines when you do it. We love pictures.