This may not be much help, but you aren't getting a ton of replies, so I thouht I'd throw it in. My 304 came with a Super-High Tech-Ultra Performance coat-hanger throttle "cable". The one I ordered from 4WD was model-correct, but too short. Luckily, they had the length of each year/model in the catalog, and so I got a bit smarter, measured how long it should be at closed-throttle, and was able to order one that works well. With any luck, maybe you can take a tape measure, see how long a cable you need, and find one that's close enough to offer full-closed and full-open on your TBI.
Just a thought...
"Damn Everything But The Circus..." e.e.c.