Unless the rest of the car can support that Summit cam I would forget about it...
"Lopey idle, mid-upper rpm power. Works best with 10:1-11:1 compression, 3,000+ stall, and gearing. Works well with N2O and roots blower. "
A stock 78 350 is not going to have the compression ratio to make this cam work as it is designed. And, if you are still running the stock converter and 2.40 or 2.73 rear gears, this car will be a slug.
I know this isn't what you want to hear but, with a stock compression late 70's 350 you really need to keep the cam mild. I would design the engine to make maximum torque off idle up to about 4500 RPM. The car is big and heavy and you need that low-end oomph to get it moving. A mid-range lumpity-lump cam is not going to do that and you will not be happy with the performance.
Just my thoughts.
Mark