[sheltonk7]

my buddy has a 454 he thinks is over 400 h.p i dont think so what do you guys think it is a .30 over flat top,109 cc heads,lunati vodoo cam 286d 572 lift,roller rockers,weiand intake,750 d.p,headers,stock dist, also it has not had any machine work such as zero deck or anything he says it is 10.0 to 1 compression but i dont think so it sounds good but revs really slow i think cam is killing it

[starnest]

Not enough information to know for sure.
For example, my 454 motor at 30 over:
Bore 4.2810 Stroke 4.0000 Rod Length 6.1350
Int Valve 1.88 Exh Valve 2.19
Head Volume 113.0000 (cc'd 114 to 122)
Cam 11-208-3 CB 280H-10
Dur@.006 280
Valve Lift 0.5200
Intake CL @ 106
Int Open 34 Int Close 66
Exh Open 74 Exh Close 26
Dur@.050 230
Lobe Lift 0.3063
Lobe Sep 110
Piston (cc) -25.50 KB 257
Using Weind Stealth manifold with 770cfm carb
Hooker Competition headers and flowmaster exhaust

According to simulation software:
rpm tq hp
2000 490 185
2500 490 235
3000 525 300
3500 565 375
4000 585 445
4500 590 510
5000 585 555
5500 540 565
6000 500 560
6500 395 495
7000 320 430

The cylinder heads are 820 castings with the large 2.19/1.88 valves, assumed is that the valves are installed correctly so that flow is not impeded (shrowded). I think the simulation is overly ambitious, but I really do expect to see >500HP at the flywheel.

Based on the info you provided, I think that 400HP is no problem, unless the heads are "peanut port" castings. Those heads make good low rpm torque, but run out of breath after 4000 rpm. These heads may explain why it revs slow, but other factors, especially timing can cause that too.

Nothing wrong with letting your buddy thinks he has 400HP, unless he's betting the farm.

[Torque454]

A 454 is pretty slow revving anyways. Its a long stroke engine. A 454 is pretty close to 400 gross HP right from the factory. Net HP is only 240-ish tho. Still yet, 400hp sounds believable from that setup.