340 cam

Stick with cams like 340 cam or 268 Comp Cams.
Note. The performer has smaller ports than the 1973 340 TQ intake has.
I know you say you have the Performer but you will be running 318 small ports on a larger 340-360 port head.
It will ne fine low end mid range but will reduce power on upper end.
I ran the Performer on my 1972 340. But was to get mileage up on my 1972 340 Challenger rally.
I also has a 8 3/4 with 271 sure grip as almost all I-10 interstate
A RPM may be better