Hey guys, longtime lurker and information leech here. I am installing a DIY TBI setup on a 1973 440 that's slightly warmed up and is currently living in a Jeep Wagoneer. I am using an early 454 TBI unit with the flat TPS connector and a '7427 PCM and harness that I got from the JY out of a 1994 G20 conversion van.

Here is where my confusion lies.

The BCC on the outside of the computer housing says BDSD. When I look that BDSD BCC up, I can only find it here: http://www.scotthansen.net/BCCLookup.pdf

BCC Year Release Date Eprom ECM Prom ID Scan ID Platform Engine Displacement Trans Trans Type
BDSD 1994 33939 16188493 16168625 8494 8465 G1 LB4 4.3 M30 AUTO

I am almost 99.9% positive the van in the JY was a V8, not a 4.3, but it has been a while. The actual memcal inside of the computer doesn't show a BCC on it, just numbers. Those numbers are: 4090 1617 4891.

The ECM is a 7427 but I noticed something was amiss when none of the 7427 wiring diagrams were matching up properly. For example, F9 for me is an orange/black wire, which seems to match the $OE wiring diagrams. That makes even less sense considering the computer case BCC says it's for a 4.3...which wouldn't have had a 4L80...

Basically, I'm just looking for some detective work help in trying to figure out exactly what I'm working with. From my reading the 7427 can run either $OD or $OE, and since my harness seems to match the $OE diagrams and I'm going to use a 7.4L bin to start my tuning, is it as simple as burning the $OE info to a chip and going from there?