In your first post you said you wanted a cam with a nice choppy lope, so you need to decide what is more important - sounds good or actually performs. Its easy to get a choppy lope, but the performance of those cams may suck if they are not matched to the rest of your engine. Go for performance, and consider the choppy idle a side benefit.
The big advantage you have is that you already have much better heads than most smog era engines. That provides a good basis for performance improvement.
A stock smog era 350 head usually has 72-75cc heads with about 8.0-8.2 compression. When you switch to 64cc performance heads you usually get about 1 point increase in compression, and you get a lot better flow than stock. It sounds like this is what you have.
Try using the Comp Cams tool and entering the specs as a 9.2 compression engine with 64cc heads and whatever valve sizes and flow you have on the Dart heads. Also enter the weight and axle ratio of your truck. Then look at the results for various cam durations.
My guess is that you will find that a cam with duration of about 218-222 will give you a really good RPM power range; however, you might go up and down in duration from there. If you need low end torque for 4 wheeling with big tires, a little less duration (214, etc.) might be better. If you want to run it harder at high RPM, you might use duration up to about 225-230. If you want to go bigger than that you need a high stall converter to get the RPM up into the power band faster. If this was a lighter car with a 4 speed you could go up as high as 235 duration, but that is probably not a good match for your truck. I have seen a lot of recommendations for high stall converters from a company called Freak Show Performance, but have no personal experience with them.
FYI - I chose to go with a Howards retrofit roller cam just for durability and low friction, but it does cost a lot more than a standard hydraulic cam. If you decide to also use roller rockers or other upgrades it gets even more expensive.
Bruce
