Arp Main valve studs (HELP)


Fresh Recruit
Morning all
Just building my forged engine (4efte) i’ve put the arp main studs in , when im putting main caps on the arp’s are not a tight fit to the cap theres a couple mm play just wondering if i should be using these or just go for OE. Bit confused
Picture below shows standard bolt above


Last edited:


Super Moderator
the picture makes it look like the thread diameter is slightly smaller. can you measure the OD of the threaded section on both?

are they genuine ARP or could you have been fobbed off with fakes?


Fresh Recruit
Im guessing there genuine arp got them from Tuning developments, obviously the standard bolts have that little lip at the top of the bolt to hold the main caps. The code on the box is for 4ag engine, Which Tuning developments say they put in there builds. Im just a tad confused has anyone on here used the same ones or just stuck with standard