You are doing a daily driver, low rpm motor, so just stay with the stock cam.
More duration will simply move the HP and TQ peak higher and cost you low rpm torque and low rpm HP.
It is very important to keep track of the lifters and get them back in the same holes. Do change out the timing chain.
Use the money saved by keeping the cam on: recurving the distributor, HEI ignition upgrade and a good coil and sparkplug wires.
