1996 Silverado x-cab with 2003 Escalade LQ9 and built 2004 4L80...minor issues...

So, I have my Silverado running on the LQ9 and the transmission is working well.

Problem 1:Only the fuel gauge and speedometer work so far. I have the correct wires connected, but the rest of the gauges are a no go. I've seen so many conflicting opinions on what I have to do to make them work, I really don't know where to start. I'd love to get the factory gauges up and running ASAP.

Problem 2:Truck works great at 1/2 throttle and has loads of power, but at WOT it tries to redline to the sky and power falls off a bit...and it REFUSES to shift. Once you let off a bit, no problemo.

I still have to get A/C back on the truck and find a better route for the intake tube.

The Caddy I stole the engine from had a hydraboost brake system and my truck uses vacuum boost system. I've plugged one of the ports on the power steering pump and used the engine for vacuum. Seems okay, but I think I'm going to swap out the vacuum brake booster for a hydraboost unit and see if that makes a big difference. I'm thinking that that isn't a stretch. I'd LIKE to add rear disc brakes and a proportioning valve, but I can do that in due time.

I've seriously considered taking it to Spartan performance and letting them work out the Gremlins, but that defeats the reason for having a project truck.

I have a pretty similar setup. I've got a '98 ecsb with an '05 LQ9 that I finished swapping last April and my post is buried here somewhere. I was also in the process of working out some gauge and wiring bugs until Uncle Sam decided to send me to Korea for 9 months. I'm itching to get back so I can work on finishing up the remaining bugs. The tach is a semi easy fix because all you have to do is hook up a resistor in line with the white wire, info can be found on lt1swap.com . The coolant temp gauge is a little more tricky but I seemed to have figured it out by using the older ls1 3-wire sender/sensor. I haven't got the oil/gas gauges working yet and I was wondering if you could post details to how you hooked those up. I used the original 98 oil sender with an adapter and I'm still not getting an accurate reading on the gauge. Your trans shift issue will have to be addressed by a reputable tuner who can properly adjust your shift points. It took my tuner over an hour to get it just right and it shifts flawlessly.