https://www.ebay.com/itm/GM-Delco-Mo...53.m1438.l2649
Will this fit in my 66? It has a 455, sitting on new motor mounts exactly like the ones originally on the 330. It has the original 1970 stamped steel 455 valve/rocker covers.

 

1967 Cutlii came with the same 11" booster as was used on the 68-72 cars, so yes it fits. The 1967 BBO cars (442 and Turnpike Cruiser) DID get one notched valve cover on the driver's side to clear, however. The reality is that the 11" booster will clear without the notched cover, but you may need to remove the booster to get the valve cover off with the engine in the car. And FYI, the 330 and 400 motor mounts were the same part number in 1965-66-67-68 (and even the same with the 455 on the 68 H/O).