[2006 editors note: The Idea was to use a TBI to save the trouble of fitting injectors to the manifold, but once I saw the TBI I knew that it would unsuitable for my application]
The GM TBI came from All American parts in Barnsley. Cost £45 -
I sheared the screw holding the butterflies on. They are burred over, you need to grind the burrs away first!
If the TBI works ok, then may consider something along these lines: