7730 vss question

Little backstory:

Back in the early 2000's we swapped the 3.1 out of my brother's 92 Camaro RS for a Ramjet 350. He bought a new Camaro and gave the 92 to our dad. Dad isnt a car guy, he prefers trucks. He wanted an older truck to build a rat rod shop truck out of. Ive swapped the Ramjet 350 into a 67 c10. The ramjet has had an lt4 hot cam installed so I adapted a TPI harness and 7730 computer from the 92 Camaro. Ive gotten this thing running starting with Ultm8Z's Miniram start bin from thirdgen.org. I posted a thread over there before starting this whole computer swap for some advice, but this VSS question isnt exactly thirdgen related so I didnt want to get my thread deleted. I've been tuning TBI swaps for offroad trucks for a while now, but this is my first time messing with TPI so Im still learning.

The Camaro had Autometer gauges in it and was running a 5291 which is a hall effect (square wave) 16 pulse pass through sensor that screws into the speedometer cable. It fits the three speed on the truck that were going to run til it pops then do a 4 speed swap. I hooked the output of this sensor to the b9 and b10. Im getting a speed sensor code 24. I figure I probably need to switch it to the optical input but its 2000 ppm this sensor is 16000 and Ive read the ppm constant doesnt change that input. Is there a way to salvage this setup? A change in the code somewhere else? I have 4 drac modules and a 4 out buffer at my disposal left over from TBI projects.

If there's nothing to save from this setup I can order a dakota digital SEN-01-4160 which will screw on the the speedometer cable and is an 8 ppr magnetic (sine wave) sensor. I know I can hook this up directly to b9 and b10 and just make the change to 8000 ppm in the tune, but I was hoping to not need to spend any more money to get this running (even the $50 for the sensor from summit, since the chief financial officer is starting to grumble, LOL)

The optical sensor input is built for 2k pulse / mile. The sine wave or magnetic sensor signal must cross 0V to be detected. There is a thread here that included a schematic for shifting the voltage from a square wave signal to drop below 0V. The attachments were orphaned several months ago but the OP may be able to provide another copy in less time that it takes me to dig out the original attachment.

http://www.gearhead-efi.com/Fuel-Inj...gnal-converter

Thanks for that. Ive PMed the op on that thread to see if he could hook me up with some diagrams.