don't call summit, call comp cams direct, get the cam part# that they reccomend, call summit and order it. the comp cams tech line will be waaaaaay more helpful in this case. i reccomend one that is abot .510 lift and 246@.050 duration, it is the most lift that stock 350 springs can handle, and the duration is short enough to make it street-able
Comp Cams has a program called CamQuest you can download for free from their website. You put in the info about your motor - type of heads, manifold, exhaust, carbs, etc - and allows you to try various comp cams on a virtual dyno to see what they'll do for your motor. The more complete and honest you are with the inputs, the better answer you get. It comes with extensive instructions to help you pick the right camshaft. Takes the voodoo magic out of picking a cam. I used it for my 340 Mopar build, and was very happy with the result.