My potential compression ratio
I know this is an old thread but I just wanted to see if the OP made any progress since the last post... I'm also building a 360 with Magnum heads much like dgc333's build and I'm stuck on cam choice. One I've been looking at is the Comp 270H, I know it was mentioned that Magnum heads have better crossflow characteristics and might not benefit from dual-pattern cams. I'm interested to see if a single-pattern like this one would produce better breathing efficiency compared to its closest dual-pattern cousin the XE268... also the slightly lower lift on both lobes and higher duration on the intake might make it even less detonation-prone than with the XE268 which dgc333 said wasn't even bad in the first place. Have you been able to play around with this yet octanejunkie?
I'm also looking to run ~3.2 gears and a 2800-stall converter so I need to find that delicate balance between keeping detonation at bay and having enough low-end torque for cruising and gas mileage.