ARP 425 or 625 head studs

M

Marq92

Member
Joined
May 25, 2012
Messages
960
Hey everybody,
I plan on installing head studs soon before I start adding more mods. Since my stock headgasket is in good shape I will be installing them one at a time using the cummins torque sequence starting at the center removing one bolt and threading in one lubed arp stud at 100ft lbs. Once all bolts are replaced with arp's then I will go up to either 125 if i get 425's or 150 if i use 625 new age studs both in 5ft lb increments. Then do the necessary retourques. My main question is if there is any downside to going with 625 studs because I think it would be worth it because the added insurance. Thanks.
 
Save up your money and do the job right. ARP 425s, new mls head gasket and a quality head recondition job.
 
Would it hurt anything if I did the 625's now? Thanks for the input guys.
 
No. For now, just tighten the stock head bolts, each 1/4 turn. You only have a super40!
 
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It wouldn't hurt anything. I would do what Lee said do a new gasket and get the head checked. I did 425s one at a time and a less than a month latter I was replacing the head gasket. My 425s hold 52 lbs of boost and I know there are guys that get more with them.
 
LReiff said:
No. For now, just tighten the stock head bolts, each 1/4 turn. You only have a super40!
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I don't have the Super 40 yet, just a smarty, but I want to make sure the motor can hold my final goals before I do them. What about the II super pahtshaft and 200's?
 
Wouldn't the 625's be able to hold my stock gasket even with my 200's and 62/71/14? Why do you say to get a new mls gasket and head recondition? I am not looking for max power, just reliability and longevity.
 
I'm just saying that I don't think I need to do something as extreme as removing the head and outting an mls gasket on when I could just remove them one at a time because my goals aren't extreme.
 
Do it right the first time. Like Lee said replace the gasket at the same time. If I were you just order the gasket and studs and let them sit on the shelf til you get everything else you want and do it all at once.
 
I ran stock head gasket/stock retorqued bolts with 500-600hp at any given time for 2 years and never had a problem. Thats not to say that you wouldnt, just giving my experience. If you want to buy studs for security get the 425s and swap them one at a time. Get a few heat cycles on them while running it easy and do a retorque. I would go to at least 130ft lbs with them as well.

The truck in my sig has a o-ringed head and new stock bolts...
 
Why scrap a perfectly good gasket? Snug them up to 145 ft-lbs and run it til it blows. Like many guys you could go several years before blowing it.
 
So you guys don't really like the one at a time method?
If i remove the head and install the mls gasket do i have to straight edge check the block and head?
 
I still can't believe H11's haven't been mentioned. They've been in 6+ trucks here over 1000hp with no issues, and are cheaper and more available than the 625's
 
Yeah I heard they are good, but why the 425's and not the 625's? I'm asking because I spent the extra dough and got the 625's lol
 
ctdiesel99 said:
I still can't believe H11's haven't been mentioned. They've been in 6+ trucks here over 1000hp with no issues, and are cheaper and more available than the 625's
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Sled puller's secret! LOL They work for me as well!
 
I have heard H-11's are better than 425's but not 625's because H-11's are prone to hydrogen embrittlement and you have to bottom tap ans I don't trust myself to. I'm gonna stick some 625's in for piece of mind.
 
Marq92 said:
I have heard H-11's are better than 425's but not 625's because H-11's are prone to hydrogen embrittlement and you have to bottom tap ans I don't trust myself to. I'm gonna stick some 625's in for piece of mind.
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You only have to bottom tap if you use 14mm, they offer 12mm's that are drop in replacements.
We made 1272hp on a stock head w/ h11's but hey do your thing bif:hehe:
 
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