I have what I was told is a 454 but it is in my blazer right now and is really dirty so I don't know how the heck to check the casting numbers on the back of the block to see what it really is. I don't plan on pulling the motor until later this summer (my brother is starting his auto body class and this is going to be his project in class, so that would be a good time to freshen up the motor) and I wanted to start collecting parts for it over the summer at swap meets and buying new ones as money permits. My question is what parts are interchangeable between different big blocks and different years? Valve covers?Cam? Gear drive? Pushrods? Is that about it?