Im currently about to start building a new motor for a 71 chevelle and have been debating on which way to go. I have heard alot for both sides of this debate. most people say the stroker is the way to go for more torque but not as reliable as a bored 350. also should i be worried about restricted redline with strokers? im looking for a around 400-450hp at the wheels. any input would be appreciated  

You can get 400-450 HP with a 355 (.030" bore) 350, depending on what you want to put in the motor.

The 383 makes great torque, good for a heavy car like your Chevelle. 383s are very reliable now that they've become so popular and good parts are plentiful.  

Outside of how much horsepower you want, what do you want the car to do? Daily driver, drag racing, weekend cruiser? I can dole out some more specific advice knowing what you really want the car to do.  

off topic here, how can i make 400hp out of my 355, w/o buying aluminum heads?  

sorta inbetween, more of a daily driver(it'll probably turn into a weekend warrior when im completely done with it but im not gonna wanna let it sit in the garage much the first couple years) but still with a drag car spirit, im gonna go to the track for fun a couple times but its gonna see its share of street action  

Then you're best to stick with a 355. A 355 with 10:1 compression, a hot ignition system, good heads, .500" lift hydraulic roller cam, etc., will get you close to if not over 400 HP.  

You want to find a set of Vortec iron heads from a '96-'99 Chevy/GMC truck. Those heads will help you get to 400HP without buying aluminum ones.  

DART Iron Eagles, or Vortecs. The DARTS can be had with configuration choices that will accept your current intake if you want to keep it. The original Vortecs take a different bolt pattern and port location for the intake, the new Vortecs will bolt to older manifolds but cost a lot more than the originals.

I go for the Iron Eagles, but you don't want old ones off E-bay. The new production has been upgraded with new technology so you want them as fresh as possible.

Bogie  

The old vortecs flow verywell too they need to be machined for over 420"s of lift. There is also 1 or 2 castings that can crack