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.