My "new" HS6 SU carbs are a drastic improvement over the old Strombergs, but some of the non-rebuild kit pieces on them need replaced as they are scratched. Most importantly, the inside of the dome (dashpot) is scratched and hindering smooth piston operation. Instead of taking the time to sand\buff them out, I would rather just swap out parts with some junkyard Ebay SUs. Unfortunately, SU HS6 carbs are about the most expensive SUs on Ebay right now, even in rusty, broken down form. HS2, HS4, and HI types are much cheaper overall. Are domes and any other parts interchangable among these different types of HU styles? Is anything interchangable between the Datsun SU style carbs and Volvo? I searched the archives regarding this question, but didn't do too well. Many thanks.