Here is my opinion
1 - Getting somewhere between 9 and 10:1 is not precise enough, especially with that 268H cam, and 10.5:1 is way too high
To make sure you maximize power and minimize the chance for detonation, shoot for max 9.75:1 static compression and don't go under about 9.25:1
This means measuring everything, he should calculate compression using a planned deck clearance of no more than .010 with a .041 gasket (common gasket for an FE), actually measure the chambers, then calculate the dish needed to get there. Buy a piston based on what you need to meet your goal
In addition, he should degree the cam to make sure it is where he expects, my calcs all were based on a 106 intake centerline for the 268, if you change centerline or change cams, the compression requirements change
2 - If forged pistons were available, I would not choose hypers.
Yes, hypers will work fine in most instances, however, failure of a hyper is an emotional event usually resulting in a lot more damage than an equiv forged, even if the forged piston fails too
Note that I said you dont NEED to go forged, but there is no reason not to, and Speedpros are as good if not better as the hypers. In the old days forged pistons expanded a ton and were heavy, but these arent the TRW/Speedpros of days gone by, they are decent pistons
As far as holding their shape better, that again goes back to the comment above, in the old days, low silicon content of forged pistons required big clearance and they grew when hot. Not any more.
As far as holding their shape, thats the problem with Hypers...when they fail, although this is an exaggeration to make a point, "glass holds its shape better than wood" but what happens when you try to bend it? A hyper fails by shattering, a forged piston tends to just roll up.
3 - The edelbrock intake is a good choice if choosing an RPM, the stock Performer is a turd and the Victor is too radical for the cam.
4 - The 750 carb is on the large side of OK, anything from 600-750 will work.
5 - Be sure to recurve the distributor, stock FE distributors have too much advance and it comes in too slow. In street driving you'll think you picked up 2 more cylinders with a good recurve
6 - If you can afford any performance head work, now is the time to do it. Port match the heads, clean up the bowls around the valve guide area, and have a performance valve job done. There are cost effective undercut stainless valves out there, search Alex's Parts on Google. It could be a 50 hp difference, even with a mild motor, with no downside on torque.
As far as who buys the parts, doesn't really matter, but he makes a little profit on the parts, you get a little better deal on the build. You buy the parts, he will probably make it up elsewhere.
The real benefit of him buying is that he will be forced to stand behind his work, if you buy it, its almost certain anything that is wrong is your fault
to 375 hp at 4,600 to 6,000 rpm. Their torque ratings are 427 pound-feet at 2,800 to 3,400 rpm. Their compression ratios run from 9.6:1 to 10.6:1.
