With those heads, some headers, step up to a performer rpm or better a weiand stealth manifold and a 650-750cfm vac sec carb, I would go one step up on cam, I am currently running a 351w. 9.1 comp Twisted wedge heads,crane retrofit hyd roller cam 212 220 524 646 112 LC's, 1 3/4 ,3/4 length try y's and have run holley projection DI on a torker 2, as well as an rpm, an edelbrock 750 and currently a demon 650 VS speed demon (the best since EFI) and it idles smooth, has massive low end,great nid and I can rev it to 7K but it doesn't really make much power past 5800 or so, I think it drops of at 5500 but it wil rev to 7k, probably because of a properly matched valvespring setup for the hyd roller.
I think for a daily driver 351w with decent heads, I would run a cam around 224 int 234ex @ 0.50, at least 220 @0.50. The comp xe 274 hr is probably optimal for a 351w, with the 112 LDA it will have a slight lope but still pull enough VAC for power brakes and trans modulator, it will kill a slight bit of low end butnot even noticable except you wont smokeem as much off the line yet it will kick ass in the mid and top end.
I'd say that cam, about 9.5 comp,perfromer heads,good headers and exhaust,a good stealth or rpm intake will make 400-425 streetable FWHP and about 400 or so ft lbs of torque all below 5500-5800 rpm.
peak HP should be around 4500-5000 and peak torque around 3500-4000.
Consider a custom cam, it will be milder but make more low end,mid and top than most bigger off the shelf cams and more VAC and better BSFC than off the shelf cams......just my 2 cents
my 67 vert http://htwheelz.smugmug.com