I built a 440 for a kid for his mud drag truck and that's what he wanted installed, a pj noisy gear drive, I told him that he shouldn't intall it but he insisted on the "noise" effect. Couldn't hear anything else the motor was doing....I like being able to hear the motor in case of any rocker arm or lifter failure or whatever else may be going on inside....the gear drive drowns it all out. Ended up killing a set of Cranes Gold Adj's cuz he couldn't hear it!!
Also I heard that the gear drive doesn't take as much vibration as the chain does, which can have a bad effect on your main/rod bearings. Makes sense being you have a little bit of flex in the chain as opposed to solid mounted gears.
Anyways, as far as cam selection goes. I'm getting ready to build a 318 for my valiant. Built the same motor in my 71 Dart (now long gone) and it was a pretty peppy ride. Everyone at the drag strip asked if it was a 340. Well going with the same build in my valiant except with more compression. The dart motor had a measly 7.9:1. Pistons were about .100 in the hole. But I was 17 and didn't care, as long as it ran ok.
Now going with 9-9.5:1, doing a little bit of head work, still going with the Edelbrock Performer intake, a 650 DP holley, and the cam is a Crane Energizer.... lift is .454/.454 with 216 @.050 Duration. Installed straight up. Also will be pulling the adjustables off the 273 for it. Cam is good for 1800-5000rpm and I used stock 318 springs. Shifted at 5000 right on the money. Dist advance was 32 degrees total.
Cam worked great, I drove it everyday, had a little bit of a lope to it and got around 12-15mpg with it. Would run 13.90's all day in 1/4 and consistent 8.90's in 1/8. That's driving it there, running it and driving it home. And the track was 45 miles one way.
Also had an 8 3/4 with a 3:55 posi. Factory converter, headers.
Hope this helps