Simply because I have yet to find a straight answer on this. What is the difference between a PR4-3, PR4-4, and PR4-5 head? I have all three. The PR4-5 is on my motor now, but is toast due to a cam bolt breaking off and not able to get it to back out. Was just going to swap out the head if there is no difference between them other than the -X digit being a manufacturing digit.

Thanks for the help in advance!

 

Correction. PR4-2 and PR4-3. The PR4-5 is in the car now, just need to know if the others will work in its place.

 

Additional question. The head bolts are brand new and motor has not ran yet. If I remove the head and swap it out, do I need to replace the head bolts. They are ARP head bolts.

 

they're going to be the exact same cast heads.
the arp's are studs, not bolts. and they can be reused, even if ran. even oem bolts can be reused. they aren't TTY

 

Thank you!