I was planning on getting aftermarket upper/lower intake, and it calls for a 70mm throttle body. Which MAF sensor would work best with 70mm TB, do they match up directly, for example a 70-70? Please assist me with this, i have never really understood this.
You have to match the throttle body to the application the car is being used, but you don't have to match the MAF and throttle body. There is a rule of thumb that you always use an aftermarket MAF with an aftermarket TB. Try to use something bigger than 73. The ones that are between 76-80mm are best.
Im running a 76MM C&L and an Edelbrock 70MM TB. The only thing that has to match up is your injectors w/ your MAF calibration. Cant run a Mass air meter calibrated for 24# injectors while still running 19# injectors. Im running #30 injectors w/ the C&L 30LB sample tube.
Unless you are using the Pro-M Univer MAF, you will want to make the diameter of the MAF about 5mm larger than the TB just to keep it from being the bottleneck.