swapping caddy heads?? help

I know that swapping 390 caddy heads and intake onto a caddy 331 is pretty much bolt on...but is there anything else that has to be done? new valves,etc.
has anyone here done this?
does it make a noticeable difference?
any help is much appreciated

 

The 390 has larger valves, they are farther apart c/l-c/l then the 331, so i think you need longer pushrods ( probaby 390 spec ). I have a set of 1960 390 heads, and although the center exhaust ports are still siameze ( sp?), there is a cast-in devider that helps direct the flow out. There are quite a few tech articles if you search for it. The intakes all interchange, so I think other then pushrods, it's a simple swap, but I'm a newby with Cad mills. Good luck.
Marko

 

There is a large difference in exhaust port size from the earliest to the latest heads, so your current exhaust manifolds may not work.

 

With the smaller bore of the 331 you may have a sharp edge protuding into the larger size head combustion chamber. Get the 390 head gasket and place it on your block to check this. This was one of the reasons I bored my 331 block as far as I could to match up the bore with its new chamber size. Mismatch can create a turbulance on compression stroke that could lead to uneven fuel burn. Also use the intake gasket to check ports on intake manifold, you can trace port size and grind ports to match head ports. You must use the 390 exhaust manifolds.