Distributor Hold Down Clamp, 1964-80 Oldsmobile V8 Distributor hold down clamp for 1964-80 Oldsmobile 330, 350, 400, 403 and 455 V8 engines. This is the original cast version of the hold down clamp used in the 60's and early 70's but can be used on Olds V8s to the 80's; replaces GM part number 383505.