OP.... this is all based upon the idea that the stock type pistons were put into the engine when it was rebuilt. The recommendations will change if this is not true. Please take some cranking compression readings ASAP and let us know what they are; we can make a guess on the piston types from the compression readings and the recommendations will be better.
If the stock type pistons were used in the engine rebuild, then I agree with the recommendation of the VooDoo cam; this is a low compression engine and higher lift and less duration are good to keep the dynamic compression ratio as high as you can.
OP, when you change cams, I would pull the heads and put in Mr Gakset 1121G head gaskets. These are thinner and will help the compression ratio. This will be good for the stock torque converter. If your engine has the standard Felpro head gaskets, these are thick and the engine is losing some compression. The fact that your heads have been milled 1 mm is good.
I would second the recommendation of a Voodoo cam; I would go with the 10200702. And some new valve springs. With the higher lift, the OP is going to have to look at the clearance between the valve retainers and the tops of the valve guides and seals.
I would also install this cam with an ICL of 106 degrees. This will put the dynamic compression ratio at around 7.25, with the Mr Gasket 1121G head gaskets. Higher would better, but that would require some engine mods.
But we really need the cranking compression readings first.
