Is there a mod that combines all css files and JS?
 

Wondering if such a mod exists for 4.2.2 that might decrease the number of calls to the server. Thanks.

How many are we talking? What do you have set in, Cookies and HTTP Header Options, the settings, GZIP HTML Output and GZIP Compression Level

TBH, if you combine many files the resulting files can be come quite large. Compressing those files takes some time and on a busy server that time will be large enough to negate the performance gain.

Looking at your page speed grades, I would worry about doing all the other things needed before attempting to do such a thing.

Cookies are enabled, GZIP is on, compression level is 1,

Add Standard HTTP Headers = no


Add No-Cache HTTP Headers = no


Thanks

Its not ideal to have the entire css or js as a single file. Its actually better for them to be multiple files, as long as you don't go crazy with it.