Build almost done, need help with a few things

Got my conversion done, 1991 scsb stepside with a LS3/TR6060 out of a 2012 Camaro and to top it off, swapped the dash to a 1998 and I've got a few issues I need some help with. First is the tach isn't working, I've got a wire in spot 48 on the X1 connector running to the dash but not sure how to tell if there's even a signal coming out, anyone know what the output should be?
Second is not sure how to get the speedometer to work, I'm using my GPS for now so I can drive it but really want to use the gauge. I tried wiring in the drac off the vss going to the computer but it's still pegged at full speed, not even resetting to 0. Is there an output I can tap to get the speed working?
Finally the brakes are pretty squishy and the pedal goes a way down before really engaging the brakes. I had to put a 1998 power booster in to get the brakes to work since the pedal isn't even close to the stock 1991 so with the completely new dash, including brackets and pedal, I finally realized I needed to put the new booster in to get the brakes to work. I didn't pull the lines, just had my son move the master cylinder out of the way while I replaced the booster so shouldn't have got any air in anything. I bled the rears and snapped off the bleeder on the front so I've got new ones I'll be swapping in the front soon but not convinced that's the issue. Anyone have any issues with their brakes after a swap?

Thanks for the help, not sure about posting links here to other sites but you can see my build thread on ls1tech.com by searching for LS3/TR6060 in 91 C1500 and you can see everything I did to get the motor and tranny in there.

Rock

Well I realized part of my problem is the SSBC proportioning valve has a pressure switch on top of it and one of the connectors is pushed up and there's brake fluid leaking from that. Gotta find a replacement and swap that out and see if that helps with the squishy brakes.

Rock