I just installed n '05 USDM top-mount on my 03 WRX with a USDM VF-39. I followed the OP's instructions and it worked for me. There seems to be no difference between the USDM TD04 and VF-39 as far as installing the USD STI TMIC. I had to bend my AC line toward the firewall and it will mount on both brackets. I used the stock USDM STI Y-pipe (MY04) and only needed the two custom hoses to install.
2.75in ID at 3" in length
2" ID 90 deg. elbow at 4in. + 4in. in length (four inches on each side from the center) "slightly trimmed"
I located some radiator hose in these same dementions and it worked to some degree to get my car mobile but I later read that radiator hose stretches under boost which wastes energy and creates a lag-then-surge kind of effect. I now ordered the hoses in silicon like I should have in the first place.
I wanted black dull hoses for an OEM look but unfortunately silicon = shiney
. Here in CA, cops can give you a $500 ticket for "modified emissions system" (I know, because it happened to me for an intake). Something to consider if you live in CA. A red or blue hose (even a shiny black hose) can cost you a lot of money and trouble.