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Hey guys! I had some questions about the internal differences between the 5 main and 9 main 327. How many parts out of my 5 main parts motor will with in the 9 main I am building? Are pistons different? Valves? Cam?

I know new parts are ideal of course, but I'm just curious if it's feasible to take the pistons and valves from my 5 and use them in the 9 to get it running this summer.

If they are both 327s, except for the crank and block, then the majority of items you mention will interchange -- with a couple of howevers.

If the 5 main had solid lifters the cam will have a different profile than the hydraulic cam used on the 9 main. If the 5 had the optional hydraulics then it will be the same. The cams will work even if improper for the lifters but obviously there would be a compromise so operation wouldn't be optimum.

Valves and other components started out the same. If the engine has had work you would have to verify what you were swapping and make sure something oversize hadn't been installed in one engine or the other.

Like the valves, the pistons and rods are the same but that doesn't mean the pistons will just interchange. Again, it depends on whether the engines might have had a ring and bore job done and something oversize installed.

Not to make a big deal but there were also some articles on necessary changes Packard had to make. During the Korean war some materials were in somewhat short supply. Rather than completely scrap a casting or an already machined block or component if it was found to be just a tiny bit off from standard, it might have been fitted with an oversize from the factory. Usually the motor number will have some sort of symbol or character stamped in addition to the numer if something was changed from standard. Unfortunately finding the info is hit or miss and a complete list of what the different symbols and letters mean are few and far between.

Thanks so much!! Both motors are 1953, both hydraulic lifters. I have the head off the 9 main already, and will be pulling the 5 main out of the car in the next couple weeks (have to finish another project to make room in the shop). To the best of my knowledge neither motor has been rebuilt, but like you said only measuring will tell.