BOLT MAINCAP 1300
I've never broken a main bearing cap bolt , but then when I build a high performance engine I like to replace them!
MAINS BOLT 1300 (grade 8) 7/16-20 X 2.75" LONG
For all Mini 1275 (except Cooper S) and late Sprite/Midget 12CC engine numbers and later engines. For Cooper S use main cap studs AEG323.