Questions from a first time engine builder

[flyin 5.8]

Here's what I've got. The questions will follow. This engine will be going into a '90 LX hatch w/C4 trans, mostly street, some strip

351w bored .040 over
crank--stock .010 under
rods--stock
pistons--TRW forged, 13cc dish
9.50:1 C/R
carb--Holley 750cfm double pumper
intake--weiand stealth
cam-- fms #a335,
.491/.509lift I/E,
spec @ .004" (SPEC @ .050")
DURATION 280/290 I/E (220/230 I/E)
IVO 31* BTDC (3* BTDC)
IVC 69* ABDC (37* ABDC)
EVO 80* BBDC (52* BBDC)
EVC 30* ATDC (-2* BTDC)
LCA 112*
ICA 109*
ECA 115*
OVERLAP 61*
1.6 roller rockers
Long tube headers w/flowmasters (need to buy)
AFR 185 58cc heads (need to buy)

First question - Desktop Dyno says 478hp @ 6000-6500rpm, 454 ft/lb @ 5000rpm. does this sound correct?

Second question - Will the stock block, crank & rods live long making that kind of power? (I've heard that 400 is about as much as you want to do.)

Third question - What kind of ET/MPH?

Fourth question - When you are looking for 400HP and get 475HP is that a good thing? LOL