I know you can run an RPM with a shaker, but it ends being bolted to the hood
Not true anymore.
Special aircleaner assembly available here.
To run in the low 12s you're going to need more cam and a lower gear, at least a 3.73 cog to move your heavy T/A.
If the car were a few hundred pounds lighter you might get there with the 3.42s, but at best I see 12.50s. Running your current combo of parts I see no better than 12.80s.
Lighter car, more gear and more cam will get you to the 12.30s or below.