Aaron, that plate you see is part of a bracket for my throttle cable. I know it looks big but its strong and keeps the throttle cable from being a safety issue (sliding around). On the Offy intake I utilized the other two threaded holes under the carb base to bolt that plate to make a sturdy mount for my throttle cable. I haven't got around to making that plate to look better, but for now it works great, very responsive.
porkchop, my sender is an aftermarket type and I was able to use 1/4-18 pipe tap (from orielly's). With the aftermarket guage kit you get some other fittings/adapters to make things a little easier. I used the smallest fitting and matched a tap for it. Do you have the dummy light or a guage? Since you are in South TX, monitoring the temp with a guage would be important to prevent any cooling issues.