I have a standard bore 400 and #96 heads measured at 96-98cc's. I'm going to mill them 0.060" in an attempt to get the CR higher.
After milling the heads you wont get the compression up much past the high 8:1 range, probably very close to 8.8:1. A good compression ratio for running the engine on the currently available premium unleaded, you should be able to drive it hard without detonation worries.
What I want is a car that sounds like a muscle car while it's idling. I'd like to have that "seat of the pants" feel from 0 to 40 mph, but the top end does not need to be strong.
Herein lies the problem. Most guys want a radical sounding idle, but also want excellent bottom-end torque. You can't have both, it has to be a compromise between the two.
A radical or 'musclecar' idle comes from cams that generally have more top-end power.
Smoother idling cams have the best low-end power.
Using a radical cam with a somewhat low-compression 400 will not result a very good performing engine, but it will idle nasty.
Using a better-matched (smaller) cam in that same engine will result in excellent street performance (low-end and mid-range), but a less radical sounding idle. A nice sounding idle, but not the radical one that scares away potential competitors at the stoplight.
For your engine that is pretty much just a stock 400 I'd choose a cam that's in between the 068 and 744. Use the Crower 60241 (215/221,.457/464", 112 LSA). It will still have a decent little lope at idle, and you'll be pleased with the performance on the street.
Performance was not great, but it did have that lopy sound at idle, which is what I wanted at the time.
Sometimes less is more. Don't pick a cam because it has a nice idle, pick one because it makes your car move out like it should instead.
