Reply to "Dyno'd the Car, Please Critique."

FWIW, you get a long-winded reply! 300 bhp at the rear wheels usually equates to about 400 at a Pantera's flywheel; not bad IMHO. You are maxed out on compression with pump gas, so your only choice is a bigger cam- either flat-tappet or roller, or use $6.50-per-gallon race gas and jack up the compression. Expect to lose about 2 miles per gallon of fuel economy with each increment of cam duration beyond your 268. I sugest calling ALL the cam grinders and telling them your plans- and budget. They are the real experts on camshafts. I always recommend a matched set of springs AND valve lifters with any aftermarket cam. Be aware that all cam grinders get their blanks from one of only 3 manufacturers in the U.S, and the last 10 yrs or so, there have been a rash of poorly-machined integral drive gears and improperly hardened lobes on 351-C cams. Since the 351-C is a low-production engine, aftermarket cams don't sell fast so there may still be some bad blanks out there. The gear problem has shown up in as little as 5 miles, failing a stock cast iron distributor drive gear, so check the gear within the first 50 or so miles. Be SURE you can return the whole mess if you get a bummer. The guarantee will not reimburse you for cleaning the shavings out of your engine or the rebuild costs.
A tuner carb will help somewhat but there will not be a huge power increase. I added a 700 tuner double-pump (jetted for a 351C at 4700 ft altitude) and picked up about 15 bhp PLUS 2 extra miles per gallon with our very similar combination of parts (A-3 heads & Ford/SVO hydraulic cam). I originally had a 600 Holley.
I recommend adding a 10-qt fully baffled oil pan to any Pantera. Aviaid and Armando both make acceptible units. Otherwise, you WILL lose the rod bearings sooner or later. Do not use anything but a stock oil pump; high-pressure or high-volume assemblies are not needed this side of a full-race engine. Melling makes a good one.
A stock crank will take around 600 bhp before giving trouble. A stock block, much the same. Your fuel line out of a stock Pantera gas tank will not support more power than what you've already got (400 at the flywheel) before running lean at high rpms. There is a 0.205" ID restriction in all the steel lines wherever the line is 'beaded' for a rubber hose. For much more power, a 3/8" or 1/2" ID line everywhere from the tank bottom up to the carb will be needed for high-rpm road work, regardless of what fuel pump you select.
Add-on vacuum pumps for drag racing (or Weber carbs) can be used, but a cleaner solution is a small vacuum surge tank that stores vacuum for panic-braking use.
Any 351-C waterpump should be able to move at least 50 gallons of water per minute, or you're limited in the cruise distance- and rpms- you can use. The best today is the $350 Meziere which is marginal for your present power level. One L.A owner with a nearly stock engine drove his Mezeire-equipped Pantera the 250 miles 1-way to 'Vegas a few years ago, and saw 220 degree water temps at certain points on the trip. He also had to cut some of the bulkhead support away to fit it in. I'd personally recommend a much cheaper, bolt-on Weiand 8209 aluminum mechanical waterpump, that is half the weight of the iron stocker. Mine is 17 years old and has not had an easy life.
The pump is not the problem in hot-running Panteras; flow restrictions (including any brass radiator) are. Over the nearly 30 yrs we've owned our '72, I've altered every single thing in the cooling system, and nothing changed engine temps except an aluminum radiator. Fluidyne makes a nice bolt-in unit that solved a cooling problem in Pat Hals' factory Gr-4 racer at last year's '08 Classic LeMans race in France. It is not a 'racing' radiator, either. Flexilite makes a fully shrouded dual-sucker fan assembly that bolts onto the backside of any Pantera radiator and keeps the engine acceptably cool around town, with shut-off thermostats for highway use. I use both these trouble-free assemblies.