The "Spot Eye" head elongation tool is specific for traditional Pontiac iron D-port cylinder heads with screw in studs from 1967 to 1979. Heads like 670 16 31 48 62 12 13 64 96 7K3 4X 6X

This tool with a 3/8 (long length) drill bit and 7/16 course hex bolt (to install tool) elongates the pushrod holes to allow for 1.65 and higher rocker arm ratio's 

Developed by Paul Spotts to ease the work load and accurately remove the proper amount of material on iron D-port Pontiac heads.

tool can also help machine shops as most do not know the amount or location of material removal 

Made in the USA 

Tool will wear out after a few cylinder heads.  

Also available is a drill bushing version that will allow multiple head usauge - see my other listings