Are model 66s bigger 99s?
 

I thought I read somewhere that the model 66 is a larger version of the 99, but can't find the site where I read it. Did singer make two different sizes for a lot of their machines?

I think it is usually thought of as the "other way around"
the 99 is considered a 3/4 size machine, and yes is it a little 66...(also a fancy 192 AKA "spartan")
the 28's and 128's are also 3/4 size 27's and 127's
and then the 185 is also a 3/4 size machine but I dont know of what.... it is basicly the 99 in an "updated" aluminum body.

Yes, the 99 is a smaller version of the 66. The 66 has been made since early 1900's, and the 99 came in around 1920.

The 99 does not have a 'true' reverse. The later models have a 'backtak' whereas the earlier models are forward stitching only.

Shari

Yes, the model 66 is a full size machine, the 99 is a 3/4 size machine. I would upload photos for comparison, but I'm not home where my photos reside.