The RHB5 series was a pretty popular turbo during the 80s (though various trims were used in various cars). In fact, IIRC, the one in the T-bird Turbo coupe was a bigger trim than just a VF7. The early 90s Legacy Turbo also used the RHB5 series but in the VF10 and VF11 trims. There are a few threads on the USMB board (http://www.ultimatesubaru.net/forum/
) about hybridizing RHB5 turbos by swapping in the larger compressor wheels from Legacies, T-bird Turbo Coupes, etc but keeping the stock housing and exhaust turbine.
Here's a junkyard turbo list that I found on the web a while back. Unfortunately it is in Word format, but if you search Google for "junkyard turbo" you will find it (it was the 3rd result for me) and can use Google's "View as HTML" option:
As you can see several cars used the IHI RHB5 (for example, while scrolling through, the "Ford Escort" listing caught my eye as it has an RHB5).