Aluminum water pump thicker?

Bolting up my water pump, this bolt and the opposite site seam to not get a bite.im thinking aluminum water pump must be a little thicker and just go get longer bolts. That's with two gaskets and backing plate, anyone run into this?

Correct me if i'm wrong, but I think the amount of threads is 1 1/2 times the dia. of the bolt.

I have no idea,but I just put in a little longer bolt and seams to be good now.

My Edelbrock aluminum water pump bolted up just fine with the stock bolts.

nickbay wrote:My Edelbrock aluminum water pump bolted up just fine with the stock bolts.

Yeah this water pump is from carsbycarl,not sure what brand. Good to know Edelbrock water pump works with stock bolts