PSI wire harness question...PT# HAR-1018

I've got a 1997 GMC Sierra Ext-cab using a 4.8L out of an '02 Tahoe. The harness is pretty much finished. I've got to extend and/or re-route the following components:

1-Alternator wire, due to Lextech's A/C bracket
2-MAF harness, due to custom cold air intake
3-both O2 sensor connectors, due to Schoenfeld long-tubes
4-factory fuel pump signal wire(green/wht) to new ecu

Here's my question. Where do I locate the following wires so that I may connect them properly? The instructions for the PSI harness, pt# HAR-1018 indicate that for the "under dash" bundle of wires there are:

1-Brown--for MIL Lamp Ground--Through Automotive Light to 12V
2-Black--Speedometer (Optional)--Speedometer Module
3-White--Tachometer (Optional)--Electronic Tachometer
4-Orange--Park Neutral Signal (Optional) *NOT NEUTRAL SAFETY*--To Ground (In Park and Neutral)
5-Purple--Brake Signal / TCC Ground--To 12V (Brakes Not Applied)


Lastly, I still need to route the OEM(and highly deleted) wire harness. It contains the bulkhead connectors for both the driver and passenger sides, transmission range switch(dr. side of 4L60E) and gauges. My hopes are to have factory ABS, a/c signal run off the OEM computer. Any thoughts or is this not needed?


Any help, photos would be greatly appreciated. This would make my father's day if I could get it to run this weekend.

Cheers,
Jose

Anyone? Really would like to finish this off and have an operational truck. Thanks for looking.

I believe all of those wires can be located right at the old PCM. You can depin them from the connectors and then push them into your new PCM connectors and not have to cut the wires. Lextech sent me a file about installing a Gen III using the original vortec harness, and to get the tach functional you need to splice the white wires of the coil and ignition control module together. I would recommend you contact him to get the file, even if you're not going to use your stock harness.

There is no reason to use the stock computer, as the swap computer can handle all of the functions. Contact Lextech to get the 0411 PCM swap file as well, and use the information in there to get the A/C and ABS functions running from the 0411.