My 1969 Ford NASCAR Cobra came with one in it and I use them on my replicas which I race. The
oil splashing up onto the crankshaft will at times cause a small loss of power plus it tends to whip the hot
oil to where it has some bubbles in it at times.
This is just my thoughts on using them and I am not an expert. I am sure that others will come in with better ideas.
Ron