I used Scott Drake chrome dip stick C7OE-6750-A and C7OZ-6754-A, 67-70 BB painted dipstick tube. To make the dipstick tube fit into the hole in the skirt of my '68 stock 390 cylinder block, I found that some work with a flat file was necessary to reduce the O.D. of the dipstick tube a little bit to create a sliding fit. This was five years ago and maybe the quality control on the tube has improved or maybe there was a variance in the diameter of the drilled hole in the block....it fits now. Just because it is new does not mean it is correct. Clark