It is funny as the parts book seems useless as it just mentions generic roll of 5/16" fuel line even under hemi. Didn't see anything in the tech bulletins. In the 69 dealer book under engine selection the hemi is listed as having "special 3/8" fuel line. I thought at some point in 68/69 time frame 440/hemi got the 3/8" fuel line to the pump. But who knows. Begs the question what did the A-12 get, since they started as 383s.
I bought a 69 A12 that was that was in the restoration process, they hadn't gotten to the point of doing the fuel line, what was painted over on the underside of the car was 5/16 with no return line. The first run , 3/29 build date , had 5/16 lines, I don't know where the discussion has gone as I haven't been active in those forums for years .
