Bore spacing is the distance from the center line of one cylinder bore to that of the adjacent cylinder. Assuming the bores are perfectly round, this distance can be determined by measuring the distance from one cylinder wall edge to the far cylinder wall of the adjacent cylinder. To save all of our Bessel Motorsports readers the trouble, here's the bore spacing (in inches) on common American V8's:

1. AMC: 4.75
2. BUICK 350: 4.24
3. BUICK 400-430,455: 4.75
4. CADILLAC 472, 500: 5.00
5. CHEVY SMALL BLOCK: 4.40
6. CHEVY BIG BLOCK: 4.84
7. MOPAR SMALL BLOCK: 4.46
8. MOPAR BIG BLOCK: 4.80
9. FORD SMALL BLOCK: 4.38
10. FORD FE: 4.63
11. OLDSMOBILE: 4.625
12. PONTIAC: 4.62