Quote Originally Posted by belaw View Post
What is the normal input from the VSSB to pin F13 on the '7427? Some sources say 2k PPM, but others say 4k PPM. And when do you need to set the "Output Speed not from DRAC" flag?
I've never measured the normal input to pin F13 from the VSSB. It seems to me, 2K is the expected input to pin F13 on the '427 PCM. I've only done the '427 PCM to vehicles that had either a '7747 / '8747 ECM's. As far as I know, the '7747 / '8747 have always been 2K VSS. I've never really noticed any difference when setting "Output Speed not from Drac" flag on the '427 PCM upgrades I've done. In the absense of "Factory Information" I've "Set" the "Output Speed not from Drac" on the '7747 / '8747 TBI PCM upgrades I've done.

dave w