Cheap 318 performance mods.

Dan the man said

I don't see anything on the exhaust lift and the duration at 0.050. If stock exhaust manifolds are used,wouldn't a dual pattern cam be a good choice?

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Look into David Vizard's videos. Dual pattern does compensate for a less than beneficial exhaust system. OEM iron manifolds definately fall into the less than beneficial category in most cases. There have been a few pretty good ones for performance engines. Cast manifolds for the OEM are inexpensive, easy to fit space wise and pretty reliable, with respect to warranty times.
Going to 40° exhaust seats aids low lift exhaust flow and thus blowdown even with a less than beneficial exhaust. This lets you use a camshaft with less duration split than commonly available on split pattern cams. Something like +2° to +4° more than the intake duration, or possibly a single pattern cam which tends to a slight bit more torque.
Exhaust lift is not as critical as intake lift. The intake on a NA engine is at best atmospheric pressure of 14.7 PSI. The exhaust at valve opening is 70PSI to 120PSI. A header designed for the intended operating RPM range makes use of the supersonic exhaust gas mass to definately improve the efficiency. Frequently dyno testing shows an improvement with exhaust rockers with .05 less ratio. Only on the dyno or track times can that be determined.