Thread: 305 head on a 350?

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I have a friend who wants to install a set of 305 heads onto his 350 this weekend. Its an old beater pickup. Not the vortec engine. His heads are roached, and instead of springing for a valve job and the waiting time to get them back, he has a set of used 305's on the bench. Other than the valve covers being different, what else would he need. I told him I thought it was a even swap out, but now I'm wondering what head gasket would be right. 350 scribe and cut or what? Input please? Thanks.

Only place you may have trouble with would be around the heads deck where the spark plug cooling hole is. Make sure the gasket doesn't cover it.Use the 350 gasket and check that the fire ring on the gasket doesn't cover this cooling hole.
By the way,,,some 305 heads have 350 intake runners and also produce higher compression.

Does he have the rocker arms for the 305 heads too? Being the centerbolt heads they might be self aligning rockers, so you would want to make sure and use those when swapping.

ya, they are complete heads. thanks.

It'll work fine, I did the same thing on my son's 71 chevy truck. On the plus side, you can get a little free compression ratio bump by doing this. The 305 heads have a smaller combustion chamber.