Please help me. Today I was taking apart my world heads, to get the guides machined to take viton valve seals. Everything was going good, I took apart the one head and there were 2 copper shims under each spring, one had 6050 stamped on it and the others were thin with no numbers. Now when I got to the other head, 5 of 8 of the inner springs were broken, and this head had different shims. This head only had one shim per spring and it read 3050. I'm confused, why wouldn't they use the same shims. I'm about ready to take a sledge hammer to these, because the p.o.s. spring compressor I was using bent. PS:don't buy the red handle spring compressor off of ebay. thanks

 

Just means somebody was through setting up installed height is all. Casting flaws, machineing flaws in both head and springs will not always give the same installed height when assembled. Be happy somebody took the time initally to set it up that good.