Just rebuilt 5.0 - why so slow - LOST power

fuel pump is stock - pressure looks good at idle but it is a bit noisy - could possibly be a concern but funds are running low since I just dropped $8K on this car including purchase, etc.... Car still not been driven much - other things on my plate - I will try to break it in more - I hate to think about taking things apart again to degree the cam 4* advanced or change the rockers - I will have to wait on that stuff. As for the question what is BG 44K - It is a fuel system cleaner on steriods - I don't waste any money on anything else - this stuff kicks - Try it one time and you are sold for life - it is expensive at nearly $20 a can but worth it - I got my supply at $10 a can in bulk and am using it every so often in all my cars.

Update - car is starting to feel better every day now - breaking it in I guess - has about 35 miles on it now and letting the BG44K work a bit. I cleaned the air filter (cold air kit w/ cloth/wire filter) someone had soaked it in something like automatic trans fluid (not a light coat of K&N oil like you are supposed to do) and it was not breathing good - used a good degreaser and lots of hot water til it came out clean and dried it - I guess this is why the MAF wires were dirty. Set TPS to .98 volts and re-set computer. I will have to get used to this E303 cam I guess - seems to be a bit slower right off dead idle than the stock cam but if i drop the clutch at 1400rpm it will burn both the tires as long as you want. Also if I am going 15-20 mph in 1st gear under light throttle and then go to half throttle both the tires will spin as much as wanted and burn a bit when second is hit. I also notice when going 40 mph in 4th gear if it is dropped into 3rd gear with a little rev it will spin both again... I will get used to it I guess - still feels like it is breaking in and the cleaner is working its magic and the power is steadily getting better - just not what I had expected right off idle - it seems to come on strong 1500rpm and above to about 4500rpm where I let off it as it is still being broke in - feels like it will continue to pull strong for quite a bit more - sounds MEAN at idle and under load - however, I guess I should have should have stuck with a stock cam since I want strong pull right off idle til 70mph - live and learn.