Yes there is hard data. Its called a piece of metal that plugs the hole. There is ZERO flow there and if you do have flow there you need a new head/freeze plug. With the LDC mod you remove that piece of metal and put a flow tube and now you have extra circulation. So you go from zero to some.hawaiiancobra,
We've been kicking this around for some time now.
And the new heads are going on my new build.
Do you have any hard data to substantiate the above statement?
If so, I would be greatly interested.