I will start with this write-up of mine.
1958 and earlier should not have a crimped tube but there is more to it than just that.
Up through 1958 the engines had a 1/16" orifice restricting the flow of oil to the rockers. Starting in 1959 the orifice size was increased to 11/32". This larger orifice offered almost no restriction. At the same time the overflow tube on the rocker connector was pinched off. Also at the same time the groove inside each rocker was offset 1/4" so it did not line up with the supply hole at each rocker. This prevented oil from squirting out of the vent hole on each rocker.
If you use 1958 or earlier rockers on a 1959-62 engine you will have the best luck if you restrict the oil supply. Chev did this on replacement short blocks by selling you a plug to put in the block to block the original oil path and a special drilled head bolt drilled with a 1/16" hole for the oil to pass through.
Feel free to ask further questions.
