Thats the original Rotunda timing adapter found on most every engine be it van or truck setup. The van engine had this adapter located on number 4 cylinder injecter. As posted, you can remove it but you will need to replace the line. On the truck engines all you need is the number 1 cylinder hard line from a van. If you have a van engine then you need the number 4 hard line. We really do not need these adapters any longer. I have the Rotunda timing meter that works with this adapter. For no good reason I have terrible trouble when reattaching the hard line to this adapter at cylinder number 1. So I loosen this adapter and then hand thread the hard line to it. Once I feel the hard line is completely hand tight I then tighten the adapter to the injecter. It works...