Technical 400 Pontiac engines.......different than Shivel-layz ,right?

The heads should have 670 on the center ports, http://www.wallaceracing.com/head1.htm . If it does you are looking at about 10:1 compression, Pontiac rated them higher than they actually are. The heads are still closed chambered, better than the '65-'66, but not as good as the '68 and later ones. They can be made to work, but it takes some grinding. For around town driving, The Summit 2801 is great cam and doesn't cost much. It's close to the 4 barrel Pontiac 9779068 camshaft. For more of racing engine, step up to the Crower 60919 " Beast ". The Crower cam is similar to the Pontiac 9779041 Ram Air cam. This is the same cam Pontiac ran in the Nascars Super Duties. Pontiac released the Ram Air engines with 4.11 gears, four speeds, and no A/C, they were fast and routy.
Stock bottom ends will go 5600 rpm pretty easy , I did for a long time and never hurt a rod or crank. Rhoads lifters will calm it down, but they are noisy, dad ran them for years with really good results and the newest ones are now adjustable to help tune the camshaft. 3.23-3.55 gears are fine for most around town driving. For long hauls 3.08 to 3.23 would be better and the smaller Summit 2801 cam.

 

I'm running a Comp 51-223-4 in my 389. Damn near perfect cam for a hot street car. Here's a link to a 389 running one. The 400 may take this cam as well.

 

Joe h you are right on, it’s almost like you know what you are talking about lol. Your dads book is by far the best Pontiac book ever printed. If you have a Pontiac you need to find it.