Heavy Duty Hose Part #'s from NAPA
The turbo to IC size listed is for the stock size and listed it for future searches.
For a transition hose, I have always used the nomex silicone type and purchased the last one from G body parts.
The last ebay IC/gn1 perfromance one kept blowing off the Up Pipe connections and the guy had already fixed the Turbo-IC hose with the type I mentioned above.
The below 2 1/2" hose fixed the up pipe issues.
Turbo - stock IC 2" is a Napa #NBH635
http://www.napaonline.com/NOLPPSE/(S...35_0177705596#
IC-Uppipe 2 1/2" Napa NBH 639
http://www.napaonline.com/NOLPPSE/(S...639_0177705613
You should be able to get away with just the 2 1/2" inch hose on all the connections. May be a lil snug at the TB but it will go since the TB is approx 1/8" larger.
Hose is sold by the foot, when you cut it for the final use make sure to cut long for each connection.
Here are some good clamps for the up pipe connections good and wide the wide clamp is the key at the TB connection.
Hose Clamp, 2-1/4" I.D., 2-5/8" O.D.; Standard T-Bolt
Napa part: BK 7051531