This A type block 3/8" unc
stud to retain the cylinder head is 11/16"(17.3mm) longer than the standard 4" type with 1.5" of thread to hold brackets for other ancillaries such as coil. Usually fitted only at the heater tap end of the cylinder head. If using
51K282 you will need spacers/washers under the nuts as it only has 3/4" thread.
Gearbox differential housings also used this stud and reference chart as follows:
Remote type case
53K266 are 4.5" long - 4 for remote now use TAM1617
53K1471 are 3" long 5/16" unc x3 or use
51K885Rod change gearbox used-
22G1834 are 4.5" long 3/8" unc with 0.375" thread rod change only x2 - use
51K282CHS2624 are 3" long 3/8" unc with 0.250" thread x3 or use
BH506181 bolt