You've got good parts, but you didn't say is this going to be street driven?
If so the biggest limiting factor you have is the gas you are going to run. With 9.0 compression 5Lbs of boost would bring your dynamic compression ratio up to 11.86 to 1, which is pretty high for pump gas at 93 octane.
In your original post on the 27th you stated 7.0 to 1 compression, if that were the case you could run up to 8 lbs. boost.
As to what pulleys you need to run, i assume when you bought the blower it came with pulleys. The normal kits say from Jegs come with 10 1/2 percent under drive at least on the 8:71 blowers.
You are not going to know what pulleys you need until you have the engine running and know what kind of boost the blower is going to make with your setup. The heads you have will flow good but also as mentioned by another poster you have to get the exhaust out also.
We just went thru this with a 383 and 8:71, with -26CC pistions and .043 gaskets. This created an 8.7 to one static. we're in the process of changing the pistons to extreme duty JE's with a -28CC, and going to Cosmedic .074 tk. gaskets. this will drop the static to 8.27, dropping the blower pulley down to 14 1/2 underdrive so it should put out 6lbs boost and will keep the dynamic to about 11.5 to 1, which with octane booster it should be streetable.
Whew!!, did i say all that.
Zip.
PS, how did you come up with 355" with a 3.8 stroke crank? what is the bore size on the blk.