The question is what are you really looking for: performance or a driver?
The crossram was built more for torque and it has small runners. It will physically work on the 327, but I feel that it would limit the potential of it. My experience with it was that I built a 355 street engine for a guy and no matter what he wanted to keep the crossram, because it looked neat. The camshaft was a Compucam with about .460" lift and 275 advertised camshaft, so I felt that it should have pulled to about 6000. It pulled hard down low, but it felt like it hit a wall at about 5000 rpm's because it was running out of fuel. He felt that was OK, because it was for his wife's car.
I would recommend at least the Performer intake, if not the RPM Performer intake, a good carburator and a good HEI distributor, because you will have to change the distributor, also.
Bill M