I am building a 400 Pontiac with 6x heads and aluminum intake for a customer. He will probably be using stock exhaust. The car it's going in is a 70? Gran Prix. Trying to use a stock converter too. I think he will be happy with a torquie cam. Comp has too many for me to choose from. I know yall can narrow it down for me. :yes: Thanks

Standard Pontiac Ram Air IV cam is the way to go.

Have you been here? A lot of combos listed. http://forums.performanceyears.com/forums/

Stock exhaust will limit the flow of those heads, so watch your selection and keep the durations on the cam fairly mild side (@220).
I've only built a couple of "street" 400's - I mainly see 'Marine" 400/455's and they respond well to most of the same stuff.
I like the HE 260 & Magnum 270H series for marine use. Either one of these is a good idleing and great mid-range cam.
I've heard good things about the newer "S" grind for the 270, but haven't used one.

I would call Comp and talk through your build and needs and get their input.

As stated you do not need too much duration in a big heavy car like the GP with stock converter and gears. Go onto the Pontiac site listed above. Crower makes a nice dual pattern grind that will work good in your combo. You might be able to use the old 068 grind, most of the GP's had the Pontiac 067 cam. Read Cliff's comments on the Pontiac website. Ram Air IV would be a real dog in your combo with a stock converter. Even in a 455 the RAIV is a bit much, even at 9.5 c.r.

You need to call camcraft cams in arden nc.Has supplyed me with cams for 12 years.Pontiac and buick cams make tons of torque.He has a web site.