Just picked up a 455 for my 77 bird, can i get good hp from this?

what i'm wondering (obviously if u got money to can build anything) but is this a good motor to build on?  Do these motors have good potential, is it hard to get hp/tq out of these motors, cuz i bought this motor and dude told me i put forged pistons, did some stock head work & a big cam, bored .30 over, 850 holley carb & said it has about 400hp.  Is this reasonable or what?

 

With the right combination of parts, you can get all kinds of torque and power out of a 455 motor but you got to talk to someone who knows vintage Pontiac motors (it is a Pontiac motor, right?). Go to the forum section at www.highperformancepontiac.com and you'll find out all you need to know and then some.  

Frist off is it a true pontiac 455 if so I will need the casting numbers off the block which can be found on the back of the block and heads casting numbers which can be found on the center exhaust ports as well as the casting code off the right front passenger side of the block below the head.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

Any of the unique BOP 455s can be built to make decent power and copious tire smoke.

All of them have a few weak points that their dedicated cadres of enthusasts and the aftermarket can address.

But you've got to know which one you've got so you'll know who to talk to about it with.

The Buick 455 is the newest design. It has a front distributor (and weak oiling, a thin-wall block, and less aftermarket support)

The Olds 455 has about twice as many valve cover bolts as it really needed, an old-fashioned oil-fill standpipe and a tight grouping of the exhaust ports (and small valves in generally lousy heads that beg for aftermarket replacement).  

The Pontiac 455 is a virtual stand-in for most other "real" (1955-79) Pontiac V8s (and is saddled with cast iron rods (an accounting decision, no doubt) and a lifter gallery that doesn't really like big roller cams. That being said, Jim Butler and other Pontiac specialists have extracted huge power from Pontiac style parts. Pontiacs have the highest level of aftermarket support).  
--------------------------------
460_BBF_Turbo-in-CC (formerly Dr511scj) "This guy has no life other than posting endlessly on carcraft.com." -- Car Craft, July 2005
-------
October 1, 2003: " I'm thinking a couple of...turbos, blowing through an old Powerstroke intercooler...on a Super Cobra Jet-head 460 would be mad cheap and make sick power."
-------
"I have no problem with your...talking to several versions of yourself...or pointing out our failure to do a turbo story ...." --Douglas "CC/Rambler" Glad