The only problem with removing the timing chain tensioner and renewing it is that the chain has the potential to jump a tooth on the crankshaft sprocket.
I recall that a couple of members had problems with the tensioner sticking from the FAI balance chain kits which caused a clicking/ticking noise (I think it was Dave Gilbert and Jimmymac).
https://z22se.co.uk/threads/failed-balance-chain-tensioner.26519/page-7#post-1234782
DId you replace both chain kits with genuine GM ones ? They are designed to last, they fit properly and the job only has to be done once.
I see Vocky has PM'ed you, but if you do require a new a new timing chain tensioner, they're available here:
http://www.autovaux.co.uk/product/12608580-chaintensioner.aspx
or
http://www.genuinepartsearch.co.uk/ just type the part # 12608580 in the search field (£69.82 inc VAT)
🙂