Default [Q] ATT rooted S4 build JDQ39.I337UCUAMF3, is installing a custom ROM possible?

Dear Community,

Let me get my specs out of the way and then i'll ask my question.

I've got a rooted AT&T Samsung Galaxy S4,
Running Android 4.2.2
Build Number

I've followed the guides for rooting MF3 s4 devices, and can verify that i'm rooted via Titanium Backup and other SU requests I am able to allow.

My question is where to head next to learn any method of actually installing a custom ROM onto my device.

I have asked this question in a number of forums where i've learned to successfully root my device, but have only received responses akin to, "not possible"

but why? or is this not true? and where would one check daily to see when a method is developed to install a custom ROM?


Thanks for your help!!
Cheers