ARP studs

[Anthony Violi]

Just purchased ARP studs 124-4003. I want to replace existing head bolts with studs on my 95 4.6 HSE. Have I purchased the correct set?

[101RRS]

The correct kit for 3.9 to 4.6 engines is 157-4301

HOWEVER - you need to research further because I believe (but cannot confirm) that the kit you have will also work.

The kit you have was originally made for the original Buick V8 and goes across to the earlier Rover 3.5 V8s with their 14 bolt heads.

The 3.9s to 4.6s only have 10 bolt heads so the 157 - 4301 kit only has 20 bolts. The 124 - 4003 kit has 28 bolts which should (confirmation needed) be ok and you will have eight spare.

I would not torque the nuts to the ARP recommended torque as you run the risk of pulling the stud out of the block (plenty on google about this). The brains trust on here and elsewhere recommend about 70 ft Ibs.

There should be someone to either confirm or amend.

[Pedro_The_Swift]

70lb's not enough Anthony,,
I did my last (after the previous 70lbers blew the gasket) at 100, overkill? maybe. but they are all still in there.
I WOULD NOT use less than 90lb.

[TheTree]

Apparently the issue with the studs being pulled out has been corrected.

ARP now recommend 100 ft/lb in three equal steps, I have done this twice with no issues

Seems like you may have a couple of bolts left over, maybe check with ARP to make sure the 10 which you need are the right ones!

[p38arover]

I thought there was a change between the old 14 bolt set and the 10 bolt.

I torqued down to 100 in multiple steps.

[101RRS]

Obviously people need to make their own choices re torque but make sure you search the web extensively first - lots of examples of studs pulling at the ARP recommended torque.

The consensus is that the ARP recommended 100 lbs is far too high and I certainly pulled at stud at about 90 lbs which required a metal insert to be installed - a helicoil would not hold.

[Pedro_The_Swift]

Its interesting Gary, the three successes at 100 are all 4.6 blocks-- not a 4L cranked up--

oh, and Welcome Back!!

[Anthony Violi]

Perhaps there is a significant difference between the performance of 215 rover ARPstuds and the Range Rover 4.6.
Opinions do vary, but I am apprehensive about using the 215 rover studs. I feel that ARP has designed the bolts to a specific application. They also charge extra for less bolts in the Range Rover set.

[TheTree]

Perhaps there is a significant difference between the performance of 215 rover ARPstuds and the Range Rover 4.6.
Opinions do vary, but I am apprehensive about using the 215 rover studs. I feel that ARP has designed the bolts to a specific application. They also charge extra for less bolts in the Range Rover set.

I agree mate, best to get the correct stud kit !

[Anthony Violi]

For the sake of $80, I would rather have the confidence in knowing I have inserted the recommended studs (157-4301). Thanks gents for your input.