Customville is a very understated supplier - they frequently have have parts for American cars (including Vettes) on 'the the shelf' that you'd never expect. The first set of Hedman headers I bought for my '68 some 20 years ago were surprisingly 'on the shelf'! - more recently I needed a metal canister fuel filter for the '68 - a one year only item I believe, (long discontinued by GM, and absolute fortune to buy NOS in the 'States) and found a almost identical late model Jeep one in stock.