I need to know the size of this bolt ASAP! I measured the bolt 5/16" Shank 20 Thread 1" Underhead Length Is what I got from the factory bolt..... I NEED to find some ARP SS bolts that are this size but can not find any? They only seem to have 5/16-18 and 5/16-24, but do have 7/16-20...am I missing them at Summit? I took my differential cover bolt which is 5/16-18 and it WOULD not screw into the water pump pulley hole, also took a 5/16-24 and also did not work, so I can't be measuring wrong? Or am I? And if I am please tell me the size so I can get some ARP bolts already. Thanks Take care

they are 5/16-24

if that does not work, you somehow managed to get a metric threaded flange, which i didnt know existed .

I am using the Stewart Stage 2 Water Pump if that changes anything. I checked Stewart's site but they did not list the information.

I used these bolts ARP-722-0750

Well, I globed anti-seize on them and bolted them in, it was VERY VERY hard to get them bolted all the way down. I had to have 1 person hold the pump pulley while I bolted the bolts in. 2 went in fairly okay, but the other 2 were like bolts from hell.

I unbolted the bolts and no threads were ruined and no signs of cross threading. They went back in very tightly but a little better than the first time.

I think this was all because they are SS bolts...