[OneOffStroker]

I just read you entire thread, and I must say that you have done a good job at making do with what you have.

A couple of things I can add is to DEFINETLY do the exhaust yourself. $600 for a shop to do it is not a good deal. I scrapped together some pipe from 2 older projects and made true duals for my '69 Suburban in a day. Cost me under $100, including new mufflers. And that was over 30' of exhaust plumbing!! I did it with what I consider to be the worst welder on earth, the $100 Harbor Freight 90A flux core welder. It's not a bad welder, just not a good one. Make sure if you get it that it has all of the parts to attach the wire spool inside the top cover!! lol
In the end, you will have a welder and an exhaust. I can suggest craigslist or a junkyard to get old exhaust systems from. Just cut and fit parts and pieces until it gets the smoke from the front o the back.

Second, you need to re-evaluate your brake switch. What you have is good for turning on the brake lights, because it is a Normall Open (NO) switch that closes when pressure is applied. The ECM needs a Normally Closed (NC) circuit that opens when brakesa are applied to serve the TCC correctly. So you need BOTH a NO switch (for brake lights) and a NC switch (for TCC)
These two sentences were shamelessly stolen from Brendan Patten's site lt1swap.com:

"Blue Connector C1:
Pin 33 - Purple - TCC Brake Switch - This wire tells the PCM when you hit the brakes. It needs 12v+ all the time, and the brake switch should "open" this circuit when you hit the brakes."

"Stop Lamp Supply Voltage - This wire should be hooked to the same wire that feeds you're brake lights 12v+ when you press on the brake pedal. THIS IS NOT THE SAME WIRE AS TCC BRAKE SWITCH THAT THE PCM USES TO UNLOCK TORQUE CONVERTER.

After those are wired, you also MUST have the TCC brake switch signal to the PCM. If this signal is not received by the PCM, cruise will not function. TCC Brake Switch Signal is 12v+ when brakes are NOT pressed, and the switch OPENS when you hit the brakes. This signal wire is at PCM connector C1-Blue: Pin #33; Purple wire."

I just though that you should be aware of this.