A 401's head bolts are that small?

[smokin binder]

Looking up head bolt spex, they show it as 70 ft lbs. That's spec for a 7/16" bolt. How will the head gasket even hold up to any booost pressure? How do the sled puller guys make em hold up? Drill & re-tap for big studs?

 

[smokin binder]

OK, I found out they're a 9/16 for a truck 401. Plus, ARP has studs for em.

 

[pwrstrokenstang]

401's in tractors have 1/2" bolts and spec to 100ftlbs. the 456's have 9/16" bolts.

 

[Pullnforfun]

401 Engines had 1/2 bolts or 9/16 bolts. Depends on the year of assembly and application. 456 genesis engines have 9/16 bolts