tab on oil pickup for the 1/4 bolt hole that is held by the oil pump body? you need to take the oil pump off the rear main cap to drive in the pickup into the oilpump i tack weld them to .less you want to bust up some parts the oil pump needs to come off the cap. the oil pump can have a 7/16 bolt or stud i use a ARP stud most of the time .with a bolt you want to make sure you do not bottom out as some bbc maine caps on #5 are drilled and tap threw the cap with to long of a bolt can load the lower main bearing and take out the crank