questions on engine rebuild

[frankzlt1]

I was going to rebuild my engine(I no its an lt1) but not spend a ton on money. I would like to keep my heads and intake possibly change the tb but not going really big on hp. I was hoping to get about 350-400 range if possible. The engine has over 100,000 on it now. Its a4 has I believe is 323 gears and a 2800 stall the car gos good but lookin for a little more bag for the buck. The engine is completely stock even still has emission crap on it. I have an obd1 programmed ecm in it now and I notice a difference between obd2 stock ecm. Just lookin for some ideas thanks everybody.