350 uPGRADES problem

I have a difficult task at hand. I am trying to create close to 400hp with a 350..The problem is that im looking to spend $400 on upgrades becuz i can do most work. I have a 97 lt1 fom a firebird. I also have a 350 block bored 30 over, rebuilt 350 heads, intake, 350 crank & crank shaft & 30 over pistons...Which motor would be the best for this upgrade..I'm looking to increase cam, shave heads..Is this possible??  

lt1's are nice, but you need more info on intended car.
i can only see maybe 375-400 hp with the older parts. but with factory heads your closer to 375hp.
your lacking much needed info, like piston tops> flat/ dome/ what cc.
heads cc. what year. what casting. if they don't have the updated oil seals on the valve guides , i wouldn't even bother with them.
ok. 420hp is possible with factory older parts, but a very good tune is required.
if your car is a 97 firebird, get a good set of long tube headers , and hiflo exuast.
try slp exuast, with hi flo cat.
you need more money.
get nitrouse go boom.

fast/cheap/reliable. pick any 2 out of 3......  

second generation small blocks--the LT1--went to reverse cooling, so you may have problems getting those heads to bolt onto the Gen1, and then get an intake to work...sell the LT1 to someone w/ a working OptiSpark to plug into it, and use that cash for a good set of aftermarket heads for a Gen1....or sell the reciprocating assembly for a 383 stroker kit.

shaved heads, means you have to shave the intake to fit, and then have to cut down the distributor shaft.  Look into angle milling the heads, which NASCAR teams did to change the valve angle, relative to the block's deck.