You can get them used for $40 to $60 on this board and may want to try the Camero BB. LS1 owners upgrade to the 3.5 inch MAF and sell their 3" ones. I recommend this sensor if your stock MAF is bad. New price is around $150.
I just began using the LT1 and trans plus with extender chip (Ramchargers). My car has never run better. The extender chip allows your ecm to read the additional airflow the LT1 is capable of measuring. The trans plus ($280) adds timing adjustments to the fueling adjustments of the translator($180). The translators are designed by Bob Bailey, TurboBob, and allow the newer MAFs to be used with our cars/ecms.