Tips? My tips are don't do it. Compression will litteraly be about 7 to 1 and NOT be a fun cruiser. A 302 or better yet a 920 casting head upgraded to 1.88 1.60 valves would be way more fun to drive. The chamber in a j head is on average about 72 CC vs about 60 for the heads I mentioned VS about 65 for what you have as well as higher port velocity than the J head. The factory basically did what you are doing with the bigger heads and added a 4bbl at the same time and only made like 10 more HP and I can tell you from personal experience TQ was no where near as good as the 2bbl. The head gaskets you are considering are way thicker than originals as well, you can no longer find the original sheet metal thin gaskets. The thinnest readily available head gaskets are the mr gasket 1121G and they are still thicker than the original.

That is a good cam if you do the other heads, it will only add to the suck factor if you run it with the ultra low compression. If you are set on running the J heads and want a cam that sounds a little better get one of the hughes whiplash cams, the smallest one they have, the tight LSA helps TQ and make the idle a little rougher.