Kennedy does make or has in the past SBC to Audi transaxles (I have an old catalog with this listing)
The V6 is not too wide for the 914 engine compartment, it's the length that is a challange for some motors.
Why no one has done it?
Audi engines are not cheap, no one makes a kit (I'm betting that 90% of the SBC conversions wouldn't be done if one couldn't buy the conversion parts off the shelf)
The early Audi V6 motors are dogs, the newer ones are nice, but for your average person, too complicated with the electronics and all.
Karl, it was the
924 that used a truck motor. The 944 is half an 928 engine (boat motor

)
Soloracer, the 914/audi hybrid should be legal for the Import Drags if I read the rules correctly