I will agree that rebuilding a stock 351C 2V to stock specifications MAY be cheaper than purchasing a modified 351C 2V.
That having been said, I would suggest you check with your LOCAL machine shops for pricing on areas that you would like to see addressed in YOUR rebuild and compare those prices with the "to the door" prices on the engines identified in these two "representative" links of modified 351C
.
http://www.ebay.com/itm/FORD-351C-340-HP-CLEVELAND-HIGH-PERF-BALANCED-CRATE-ENGINE-/201012664634?pt=Motors_Car_Truck_Parts_Accessories&hash=item2ecd49d93a&vxp=mtr
http://www.ebay.com/itm/FORD-351C-445HP-CRATE-ENGINE-w-ALUMINUM-HEADS-BY-TUFF-DAWG-ENGINES-/161189919462?pt=Motors_Car_Truck_Parts_Accessories&hash=item2587aafae6&vxp=mtr
Good Luck with whatever approach you decide to take.
BT
He didn't specify which crate engine he was looking at, which is why I mentioned the "additional expenses" of going with a crate engine. Could be a roller cam 5.0... could be a Rousch 428... who knows, as he also said he didn't care about keeping it stock or original.
Wow BT - those Tuff Dawg engines run anywhere from $4400 to over $10K. Geez - for that kind of money, I'll happily rebuild his engine. Even with $3200 in machine work (piston mounting, cam shaft bearing installation, 3-angle valve job, balancing, blueprinting, CNC-boreing, and the pistons & cam kit itself), I'm only a total of about $7500 into my engine... and that includes everything in the engine bay. Stuff like intake, carb, coil, distributor, engine mounts, pulleys, brackets, PS pump, alternator, radiator, hoses, clamps, hardware, etc., basically empty engine bay to a running engine... minus the exhaust system.
I say he should rebuild it - he'll save money and learn more about his car in the process. Just my opinion, though.