[Yukon Jack]

3" pipes will probably be too much exhaust, unless you meant a single 3" rather than duals. I'm running a 400 sbc in my K5 with 2 1/2" duals and the repo Corvette ramhorns and it makes for some real nice low torque. The cam is a Melling MTC-1 RV with:

Degress .05" dur 204 Int. 214 Exh., Degrees ADV. dur 278 Int. 288 Exh., Inches Valve Lift Int. .420, Exh. .443, Degrees Lobe Center Int. 107, Exh. 117