My 67 has a 355 with edelbrock air gap intake, AFR 190 heads, 9.5:1 compression, Holley 650 carb, afterburner headers, 2 1/2" exhaust, 3.73 gear, 700R4, and 2500 rpm stall with lock-up. I have a comp XE270HR hyd roller cam (218@.050) with 1.6 roller tip rockers. I get 17-18 mpg and 13.08 at 108 mph in the quarter. I would use the split pattern XE cam over the single pattern cam for a street car. A friend of mine has the XE 262 cam in his 355 and he loves it.