what is the main difference in a small block chevy oil pump and an LT1 oil pump?they sell the small block pumps with a 3/4" pickup tube. why cant i use a standard small block oil pump?

 

Old small block oil pumps have a smaller pick up tube hole in it.. The LT1 oil pump has a 3/4 hole..

 

so if i get a hi performance small block pump that has a 3/4" hole i am basically getting a hi performance LT1 pump?or one that will work fine? because summit has small block pumps with the pickup installed for cheaper than the LT1 pumps with the installed pickup. like this one... http://store.summitracing.com/partde...5&autoview=sku