700R4 To TH350, speedometer off... also tick/knock sound

[dwatts1984]

So I had a turbo 350 swap done on my truck. I love it. Although I miss the one gear, no more worries of the TV cable. Anyhow, when I noticed that I have to drive the truck at 55mph to get it to go 45 mph. I'm under the impression I can just swap the speedo gear in the trans, however I have no idea what gear to go to.

No idea what the stock rear end in my truck is.
Truck: 1986 GMC 1500 single cab LWB 5.7L 4 Bolt Main V8

Any advice or help would be greatly appreciated.

Also recently noticed a ticking or knocking from under the truck. Truck has always been maintained well. Seems to have happened just after the trans swap. I dont think its the bottom end of the motor... Sounds more like the torque converter or flywheel. To be honest IM curious is anyone else has had this happen. I know the sound is typically a bad bearing in the bottom end. However like I said really sounds to be more on the tranny side.