I like those pistons. I used the KB232 D-dish with quench pad and they added alot of extra machine work to get them set up correctly.
I checked the numbers you posted and they look good, I got 9.41:1 compression?
Your tire height looks to be about 26", so with the 3.55 gears 65MPH would be about 3,000 RPM.
With your car weight, converter stall, and gear/tires size you could go with the XE274 cam.
On the dyno simulation, it does not show much difference between the XE268 and XE274 cams. I think the simulation may be limiting upper end power because of the exhaust flow numbers I used (147cfm@0.500".)
When the cams were installed per spec at 106 intake cl, the xe274 gives up about 4hp at 2,600-2,800 RPM (your stall speed), and only gains about 3HP at peak HP around 4,400 RPM. The xe274 stays around peak power longer before dropping off.
Because the simulation thinks the exhaust is a bit restrictive, advancing the installed CL of the cams (102 degrees looks good) improved the power output of both cams.
With the xe274 cam installed at 102 degrees I got peak HP of 317@4,400RPM, and 410 ft/lbs @ 3,400 RPM. I then entered the flow numbers of the Edelbrock heads which have pretty good exhaust ports, and with only that change the output went to 367 HP@5,200 RPM, and 420 ft/lbs @ 4,000 RPM.