I think it was just 2500 units for 1970, since that's how many Javelins were made.
From the SCCA handbook circa 1970:
"Cars shall conform with the provisions of the SCCA Sedan Category
Automobile Eligibility - SCCA Sedans shall be those makes and models of cars which are recognized and homologated as follows:
1 - Cars over 2000 cc displacement. A - Homologated by FIA in Group 1 or 2 prior to December 31, 1968. B - Recognized by the SCCA in Sedan Category prior to December 31, 1969. C - Recognized by ACCUS-FIA as eligible for SCCA Sedan Category after January 1, 1970.
2 - Cars of 2000 cc displacement or less. A - Homologated by FIA prior to December 31, 1969. B - Homologated by FIA after January 1, 1970, except that SCCA shall not recognize optional equipment or specifications produced in quantities of less than 1,000 units.
3 - Regardless of ACCUS-FIA or SCCA regulation as above, the following categories of cars shall not be eligible as SCCA Sedans: A - Cars with a wheelbase of more than 116 inches. B - Convertibles or sun roofs. C- Independent rear suspension on cars with engine displacement of over 2000 cc."