Well now you got me goin on the 500! I've got a 73 500 cad. While down in Georgia, while at Jones (an awesome junkland!), I found a 68 Cad. I yanked the heads. I knew that if you put the 68-72 small chamber heads on a 73-76 block ( flat tops), you get 12.6/1 compression. Now as long as you don't spin the thing much over 5000 rpm, the short block is almost bullet proof. With stock bottom end 73-76, stock heads 68-72, a set of valve springs, the new lumpy Crane Cam, the new Edelbrock performer RPM, and a set of headers this combo made 480 hp and 580 lb/ft .......... UNDER 3500 RPM!!!
Now thats some low end for the street if I ever heard of it. Just hook it to the ground and you've got a street terror for about $1800 = BYE BYE MR. FORIEGN TUNER