Question about cams..... single pattern vs split

As the ratio of exhaust flow to intake improves the need for split patterns diminishes. Split pattern cams hold exhaust valve open longer to help overcome a weak exhaust port, or possibly a restrictive exhaust system. With good heads such as Trick Flow I can't imagine wanting a big split in durations. My W2 head 408 uses a custom ground cam with a 4 degree split, most shelf cams are around 6. Using a large split with a very efficient head may even have a negative effect of over scavenging the cylinder. Since you are building a custom engine, may I suggest a custom cam ground for your application, this is how I went. We have been very pleased with results.

I am in no way an expert or guru, I just love to tinker with this stuff. If I am wrong here I hope some of the more experienced will chime in on my comments.