ebay intercoolers?
I used a 4" to 3.5" reducing elbow to go from the TB to the MAF and a 3.5" to 3" straight reducer to go from the MAF to the 3" charge pipe. The 4" clamp had to be tightented ALL the way down to get on the TB, so it's probably smaller than 4", but it's definitely bigger than 3.5", I'd say.
this might help.
also heres pics of my set up.




hope this helps.
heres where i put the coolent tank.







