As the pictured AJ's tires show, they weren't $3.They were pretty widely used in 1966, but on slicker tracks, so maybe not appropriate for the American tracks.
Our local track in Chicago had a formica surface, so silicones were about the only tires that really worked, until the microcell tires with glue came along. I still remember getting a Cox Lotus 40 and it would barely make it around the track until I laid out an extra 3 bucks for AJ's silicones.
Reading through the Coast to Coast columns in Car Model, you do hear about a fair number of tracks using silicones. As Matt points out, the advantage is that they work on a clean track. Some tracks had banned glue, so it was the go-to tire.
Don
Possibly the Cox Sil-Sliks on the mag wheels were $2.49 pr.
I'm trying a picture if it said 1.98 or 2.49 on the little piece of cardstock, in the cool tube they came in.
Anyway, NBD
My local raceway was all silicone for the first three or four years, I want there.
Glue was expressly banned.
They finally started allowing glue when they purchased another track from a local closed raceway that probably was already full of glue.
Plus, a "serious" racer, Csaba S., had just moved to the Chicago area, from Texas, and he had a pretty strong influence on our owner, Charlie.