Ok, like I said earlier, I'm putting my 1968 droptop 400ci bird all back together. I have the engine 95% done and she's almost ready to be dropped back in. My question is this... Should I put in a stock style cam shaft or put in a RV performance camshaft? What will the difference be in performance between the two, also gas mileage and general streetability between the two? I imagine that the stock camshaft would do but I also don't want some rich spoiled 19 year old kid smoking me with his modified turbo charged rice burner. I'd appreciate any input on this matter or any other performance tips. Thanks!

Tell us about the rest of the car: Gears, trans, carb, intake, heads, etc.

Q

The car is an unmolested all original configuration convt with standard 400 CI engine, pontiac Safe T Track, automatic trans three speed turbo 400, original rebuilt 4bbl Quadrajet. I don't know the gear ratio as I am not that much of an expert but I do know that it is all stock and has never been touched. The engine had a .30 overbore and I have since rebuilt it. The orginal heads have been rebuilt with three angle valve job, new valves and hardened seats. I am using the original reconditioned exhaust manifolds and intake manifold as I am trying to keep everything original.

Go with an 068 or 041 grind only if the 400 is original with large valve heads.

You install an 068/041 in a 2 bbl headed 400 and you'll fall flat on your face.

A "RV" cam? as in road vehicle...camper?

If so, unless I am missing something..Low lift, RV for torque only low end. Stick with Comp Cams, or Edelbrock. Try the Performer RPM grind.

Need to know head codes, intake cast # and carb code.

A cam that has around 210 degreees intake, 220 degrees exhaust duration @ .050" with 112 lobe centers and around .450" lift max. should work well for most mild 400's and give good throttle response and reasonable fuel economy. If yours is originally a 4 bbl 400 you should have at least 10.5:1 compression ratio and you can bump the duration numbers up another 5 degrees (215/225), which is very close to the 068 cam (068 has about .410" lift).
I think the Edelbrock cam mentioned is a copy of the 041 cam that has 230/240 degrees and .470" lift, too much for most and the heads have to be set up for this much lift.
For regular street use, make sure that the distributer has been properly recurved. The advance curve should start at about 1200 rpm and be all in by 2500 rpm. Rough timing numbers would be 12-14 degrees initial and 36 degrees total, so the mechanical advance needs to have 22-24 degrees at the crank or 11-12 degrees at the distributer. Vacuum advance should start at 6" of vacuum and be all in at 12", with about 12 degrees crank advance. Remember this is a starting point and a good shop should be able to get this razor sharp... Listen for pinging very carefully!!!