I don't think you will get 450 hp with stock heads with 1.94 valves (unported?) 9.5 compression and a RV cam

 

I didnt think so either. This one says its 469 hp for $3500

469 horsepower @ 6,000rpm
446 lbs/ft/of torque @ 5,000rpm
shipping $100.00 in Continental US only with buy it Now
This engine comes completely assembled with a balanced rotating assembly .The balance rotating assembly includes:crankshaft,pistons,rings,connec ting rods,rod bearings, flex plate & balancer.
350cid (4.000x3.480)
compression ratio 10.00 : 1
valve sizes(intake 2.02 exhaust 1.60)
New Scat crank with one piece rear seal
New Comp hydraulic roller cam
New SEALED POWER RINGS
Speed Pro engine bearings
New SPEED PRO flat top two valve relief pistons (.030)
New SEALED POWER double roller timing set
New SEALED POWER high volume oil pump with welded pick up screen, steel drive shaft & steel sleeve
New one piece rubber oil pan gasket.
New hardened push rods
New roller rocker arms
New brass expansion plugs
New ARP connecting rod bolts
New EDELBROCK (victor jr.) intake manifold
FEL-PRO gaskets
New Bow Tie black crinkle (valve covers, timing cover, oil pan)
New World Product or Dart high performance heads 67cc
The block is hand picked seasoned 4 bolt main 350ci.bored (.030). squared & parallel decked.Cylinders plateau honed to within .0001 straightness & roundness. cylinder sonic tested for thickness