360 Help

What he said.

Theres nothing wrong with a single pattern cam, nothing at all. A dual pattern cam helps the exhaust side breath in which it normaly lacks in flow vs. the intake. A dual pattern cam also works well with a ported head but there is a case of to much. It isn't allways the best for the engine.

I myself currently am running a split pattern cam in the stock headed 318. The split is large @ 216 - 228 @ .050 on a 112. This cam is very good for a first step improvement on a 318. (It should be good for mid to high 14's.) Though the current '79 mill lacks comprssion. It could go to 9.5-1 and do very well.

IF I was to use well ported 318 or stockish 360 heads and intake up top the teen, the split I would choose would be less since the heads breath alot better and at a higher RPM. A raming effect would start to take place and would be a bennifit along with the larger higher flowing heads.
(Also understand that the 318 bottom half would have to be updated with higher compresion pistons.) The centerline would also come down to 110. A narrower C-line ad's top end pop. (A few HP) I wouldn't go less than a 110 on a 318 unless it was a circle track car. Street and drag cars would stay there @ 110.
With a basic porting, the split can come down to a 8* split while a very well set of ported heads could come down to 6 or less. If your racing, there is little need to run a split. You may find power with it, you may not. It depends on how far the head is worked.

Racers will spend $200 a pop for a cam to look for a few tenths. For them, it is not a big deal to do this. For the ave. street guy, it's not worth the pains or argument.