"... I don't think it is as high as 9 to 1...I am going to check the 4x heads and see how big the chambers are supposed to be..."

I think a stock 4X head 400 had less than 8:1 CR. And, if it was rebuilt with the "8 eyebrow" pistons, it could possibly have even less comp than original. This site shows that all '73 & '74 400 engines had exactly 8:1 CR.

http://www.thepontiactransampage.com/engspec.html

But, online info differs.

http://www.hotrod.com/articles/0312pon-4x-6x-racing-heads/

http://www.crankshaftcoalition.com/wiki/Pontiac_V8_engine

http://www.wallaceracing.com/cratio0001.htm

http://www.wallaceracing.com/cr_test2.php

As mentioned, the Rhoads will give you a smoother idle.

The small Voodoo cams were designed to give the low compression engines more cylinder pressure. So, one of these will increase your power.

A Voodoo 256 will give you lots of low end torque. But, the Voodoo 262 will have a healthier sounding idle. And. with a manual trans and 3.55 gears, would probably make a good low comp 400 engine.

http://www.lunatipower.com/Product.aspx?id=1775

http://www.ebay.com/itm/New-Hydraulic-Lifters-Oldsmobile-Pontiac-260-307-350-389-400-403-421-425-428-455-/282638420185?hash=item41ce9008d9:g:JDoAAOSww9xZODlz&vxp=mtr

But, you need screw-in studs & stronger than stock springs. Some 4X heads had screw-in studs, & some didn't.

http://www.ebay.com/itm/VSH3-Pontiac-PERFORMANCE-valve-springs-400-455-389-350-428-GTO-Firebird-/282638420180?hash=item41ce9008d4:g:hvgAAOSwB4NW0LgK&vxp=mtr

A 256 Voodoo can get by with weaker springs.

http://www.lunatipower.com/Product.aspx?id=1774&gid=287

http://www.ebay.com/itm/Pontiac-V8-stock-valve-springs-400-455-389-350-428-GTO-Firebird-/272833753101?hash=item3f8628b00d:g:LYAAAOSwmrlU0mJ9&vxp=mtr

Paul Spotts & many others recommend having your heads machined for positive valve stem seals, if you don't already have 'em.