Lets take an example engine... a 327 w/ 9.5:1, pocket ported camel back heads, dual plane intake, small tube headers, intake lobe in the 210-220 deg range at 0.050".

Would an engine like this make more midrange torque with a single pattern, or a dual pattern cam with more exhaust duration? What kind of LCA would work best for this kind of application?

I'm anxious to hear everyones theories / experiences.

There are a lot more variables here than the cam, but Isky likes the single pattern cams for torque.

What is your primary tube length and size? Collector configuration and secondary pipe length? Is there a secondary junction, like an x-pipe or H-pipe?
What is the intake runner length and volume? Include the intake manifold runners in this calculation.

The wave tuning of the motor will have a much more profound effect than slight variations in cam timing.

Junk Hedman 1.5" unequal Primary headers for a Chevy II w/ 2.5" exhaust (I plan to add an H or X-pipe), and a Performer RPM Q-jet is the specific combo I am using.

I lack fabrication skills / equipment, so I am stuck with an "off-the-shelf" exhaust. Therefore, any real wave tuning is out of the question.

If it's torque your after in a range a like that...
personally I would opt for a single pattern over the dual pattern. The earlier opening of the exhaust wont really help you until the higher RPM ranges...
If you need maximum torque in that range the earlier opening exhaust will shorten your power stroke and lose you some torque.A modestly narrow LSA closes the intake sooner...( building torque ) and opens the exhaust later ( again building torque ).. If I had to run a dual pattern I would try to keep the seat durations spread within 4 degs or so. I would avoid anything with 10 or 12 deg longer exhaust...That " May " help some in the upper RPM range but generally at the expense of low to mid range... And if it's a 2 speed you'll need the extra torque. graemlins/thumbsup.gif

I guess my thinking was correct, because that is kind of what I thought. I am eyeing the 264 Isky Megacam. It is 264/264, 214/214, .450/.450, 108 LCA. I'm thinking this may work well, but I need to do more research and give it more thought yet.

Midrange will be VERY important, as it is for a 2-spd car. I'm wondering if a 2500-2800 converter and this cam will do what I need? smile.gif