Im trying to put my 408 together and my stock windage tray isnt fitting. It is hitting the rod bolts. Im following an ls motor building book and it says to bend the tray at the spots it hits. Ive been ******* with this piece of crap for over 3 hours!!!

Is there anyway i can get the stock one to fit? Do i just have to buy an aftermarket one?

 

The stock one will fit fine. You can shim the windage tray for clearance or do the method you described. Either method works, but shimming the tray will push the oil pump pickup closer to the bottom of the pan, so you will have measure it for proper clearance. I chose the second method. It's really easy, just takes time to get it right.

 

do you know what size washers/shims i need?

 

yes. go to a hardware store and buy some washers that will fit over the bolts. Somethings are not cut and dried.