1985 Pro Miyata conversion to newer groupset
I have a 1985 Miyata that I believe is in need of some upgrades. It no longer has the full Suntour groupset as it went through some changes in the ealy 90's. It has some Shimano 600 for the index shifting that was cutting edge way back then. I would like to install some STI shifters now. I was able to upgrade from a 6-speed to a 7-speed cassette on it then. Can I get a 8-speed on it now? Or can I go 9-speed? Any advice welcome.