My 69 340 swinger is about 9000 serial numbers later than MaxwellWedge, and the motor was for sure blue. Even though the engine had been pulled and modified, I bought the original valve covers, oil pan, intake, manifolds, etc... 15 years before hand...and all were blue, rather than the lighter turquise. Looking at the build sheet, is the 709 the build date. Order number 176545.