Ford V8 289 / 302 / 351 Windsor,(For Aftermarket Cylinder Heads - Fits GT40) Large Square Port, 2" Bolt Hole Spacing, Header Applications, 2/Set 1-1/4"w x 1-5/8"h Square Port. 2" Bolt Hole Spacings on each port. 289, 302, 351 Windsor. For use with aftermarket Cylinder Heads - Fits GT40For AFR Heads use PN 3083. Cross Reference: Fel-Pro 1415 Cross Reference: Edelbrock 7227.