OK, well that makes it more of a compromise as most daily driver use drives you to a lower cam duration (better low RPM torque) and most drag racers want higher cam duration (more peak HP). Understand that I don't drag race but like a road race/rally type of engine which emphasizes a wide torque band over raw peak HP. So I tend to go lower on duration and wider on LSA to preserve low RPM torque, and it colors my opinions a certain way. I care very little about 'sound' as a 2-1/2" dual exhaust will makes it sound good IMHO with even a mild cam.
Maybe here are a couple things to think about while you decide that may help you zero in on something:
LSA - Lobe separation angle will typically be in the 110-114 degree range for smaller cams like this. A smaller LSA will tend promote higher RPM HP and have a rougher idle, but at the expense of fuel economy and low RPM performance. So smaller tends to make it better for drag racing and higher for cruising and daily driving.
Ramp rate - Fast moderate or slow are ways to look at that. You can get a good idea on ramp rates by subtracting the .050" lift duration number from the advertised duration number. In the range of the mid 40's is a fast ramp; around 50-ish is moderate; high 50's and more would be slow. Fast ramps (Comp XE and Lunati Voodoo are examples) get the valve open faster and allow better cylinder filling; that tends to help mid-range and upper RPM's the most. Fast ramps can also make a shorter duration cam act like a bigger duration cam but without as much adverse effect on low end torque, so that is nice for a mixed use situation like yours. The downside is that fast ramps put more pressure/stress on all parts of the valve train from the lifter-cam lobe interface to the valve. So will tend to be more prone to break-in failures or long term wear.
- Engine compression - Even with your rebuild you likely have the classic low CR 318. The issue there with too much cam duration will be to make the engine 'doggy' at low RPM's. You have that 3.55 rear gear so that will help make up some for that, but it sounds like you have the stock torque converter, which will tend to make the engine bog more and more at low RPM's if the cam duration is too long. (And you will know this problem when you feel it... with full throttle, the engine will just 'think about' revving up for a bit, and then 'BAM', when you hit a certain RPM, it will blast off.) So that is why the cautions against going too long on cam duration; for example, going from an RV cam to a 268 cam is 2-3 'steps' up in duration and that will be a big change and you may well be disappointed in the low RPM performance.
As a reference: If you indeed have an RV cam now, then it will likely have a 112-114 LSA and advertised duration in the 240-250 range. Lift will typically be lower too; so just going up 10 degrees in duration to the 250-260 range will get you at least .020" more valve lift, which will help performance all over.
I personally would go with the Crane H-260-2 cam which is danged similar to the Comp CL20-416-3 Dual Energy one recommended in post #8. I would consider either of those to be 1 step down from the cam you originally suggested and have slower ramps for less vavletrain stress. Your initial cam selection's fast ramps would have a rougher idle and higher peak HP but be lower on low RPM torque.
FWIW....
