Help building motor?

I know pretty much nothing about actually building a motor. I am ready to start buying parts and want to know what to buy, where to go, how much it will cost, etc etc. Anybody kind enough to help me build what I want(ie what parts I will buy, etc)? I have a complete 350 2 bolt lying around that is a stock bore but needs rebuild, and a 400 short block with rotating assembly that is a stock bore 2 bolt and it needs a rebuild as well.

What I am looking for:
I would like to build a 450ish horsepower motor at the crank that will like a decent shot of nitrous for when I am at the track. Is a forged rotating assembly from like eagle the way to go? Is it better to piece a new crank/rods/pistons together instead of the kit? Do i need forged? I don't really want to spend the money on forged but if I have to, I have to.

I plan on taking the block to motor masters for the machining unless somebody has better advice. Hell if somebody had a complete new motor that they are selling I might even just be interested in that instead. Or is buying a gm zz4 crate motor just a much better way to go?

Also, does anybody do gears around here? I just bought a 10 bolt posi disc rear and I want 3:73 gears put in. Any advice on all of this is very appreciated. Thanks BCM!

I'm going to say that for a SBC, you can probably just use the kit. Go with a reputable company, and get forged internals, especially for the power + nitrous you're looking to run.

if you are careful with the tuneup,a cast rotating assembly is OK,but forged is the way to go if you plan to step up the power in the future.
do yourself a favor and sell the 10 bolt stuff you bought be fore you break it. Its time to spend money on a REAL rearend.

LOL i should have specified the 10 bolt rear that I need gears in is for my normal mild street car. For the car i want to race i'm not looking for anything super crazy, just something to drive on the street and have fun, race once in a while, and be able to pull up on newer vette's and shit and blow em away.

what is your budget for the engine?

I guess it all depends. Maybe to keep costs down to acheive my 450hp goal I could do cast stuff with higher compression and no N20? Budget I suppose would be under $2000 for the shortblock if I could?

Whats the casting number on your 400? 509 is the good one, 817 is also good, all the other 2 bolt 400s were pretty weak.

My 400 is sitting at kilpatricks right now waiting on me to get the money to build it. I'm doing pretty much what you are but a little more. I figured if I'm replacing the rotating assembly I might as well make it a stroker. Thier pricing is really good, better than buying from summit even.

PonyKiller87 if you could please pm me with what the motor is costing you (machining etc) My block is a 509 casting.

if you decide to run the 400 block/crank,you can use the stock crank with no problems at the level you are looking at. I would suggest a set of aftermarket 5.7 or 6" rods though.
the 2 bolt is plenty strong,get yourself a set of main studs,have the block line honed and zero decked.