I have a 7045738 Rochester that I can't find a rebuild kit for. I have broke the model number down into this: 70- Rochester 45-1975 7- 3-Cadillac 8- Automatic The 7 (emissions) is throwing me off. 2 indicates Federal and 5 indicates Cali. Why and where is this 7 coming from? Should I and can I just purchase a 7045238 rebuild kit since I don't need emissions or high altitude? Or were there items in the manufacturing process that may require me using the specific 7045738 kit? I am assuming that since I know the year of the carb and I know I don't want emissions that I can get away with the 7045238 kit. Any thoughts?