Ideas on what's causing my click/tick/rattle noise?

Chrysler used a PC seal that went over a stock guide OD in at least the "452" head('76) B-RB era, & fit inside a single w/damper spring, they are std. & come in the headset. If the guides have been replaced (not lined), they would be 1/2" if they machined the OE down completely, if not the PC's above should work. There are lots of PC's for the 1/2" OD, & modern design/materials.