Total power gain from these mods?

[crazy_canuck999]

Hey guys, I think next month I'm going to be adding some bbk equal-length shorties, bbk o/r h-pipe, and a mac catback, and maybe a set of the march power + amp series underdrive pullies. About how much will these mods add up to for a RWHP gain, and will it be noticable? If I have clogged cats now, will the new o/r h-pipe give me an even bigger power increase?

 

[85GTlover]

You should feel the pullies combined with exhaust.
To be realistic be happy with 15-20hp. I would
say more to be optimistic but then you get less
than you expect. Fair right?H pipe alone sound
maybe, but I doubt you "feel" it 1-3hp?

 

[88stangmangt]

i would say easily 10 to 20 to the wheels.