There are rumours floating around that the TD04 turbo like the one from your 4BG1T is related to the Holset HE221 which is getting rave reviews as a fast spooling single turbo with a decent boost capacity.
The HE221 is from the 170hp Cummins ISB engine. Basically the last iteration of the 3.9 litre 4BT. Later models gained capacity.

