A-Series ARP HSA11 Head Stud Set.
Used by KAD and recommended for all performance A-Series engines.
High-quality materials ensure cylinder head can be tightened down effectively and studs will not stretch over time.
Set includes 11 head studs. We recommend modifying your engine for the extra 2 studs.
2 Lengths of front studs are available -
Standard length - for road base engines where threads in the block have not been deepened and minimal skimming from both block and cylinder head.
Long - used on all our race builds, requires extra drilling and threading with the block and counterboring for better stud location. Measurements of studs are as follows -
Total length – 4.250”
3/8UNC / Block thread – 0.700”
3/8UNF / Head nut thread – 1.250”
Head nut and washer height – 0.500”