I bought an MS4 cam and ordered a set of LS7 lifters. The guys at the dealership showed me that the LS1 and LS7 lifters were the same part number. But I was also told by another friend that if i was running the LS1 lifters, to go with 7.4 pushrods and if running LS7's, to go with 7.375s. Anyone have any ideas?

 

Don't listen to your friend and measure. If anything it would be in the 7.425-7.500 with stock gaskets and stock shortblock.