how much total lift and duration can i run in a ls1 with only changing valve springs and not having my valves clearenced?

 

theres like 1k threads on this

 

There are indeed a lot of threads on this, but they all tell you the same thing.... NOTHING!

There are no set numbers. It varies for different applications. The agressiveness of the lobes, the advance, the LSA split, etc...

That being said, practically all the popular big cams fit the stock heads. T-Rex, MS3, MS4, G5X4, Ron Jeremy RJ-15, Texas Giant. I think anything that would not fit under a standard head would be a special order cam, or at least be noted as such (in case of stroker cams)