Came across another Kind of a silly detail on the 572.

As some might recall, the first run of these had arp main nuts, but Mitchell sourced the studs from who
Knows where. They were never called out on Mopar's bill of materials so wasn't much I could research.

Though I hadn't personally come across any issues with the main studs...and no customers directly complained of trouble
I thought it best to replace the 10 main studs on my '08 block being that some folks claimed they could potentially
Be rubber.....

So I went about trying to purchase just the studs as we did around here in '08/'09 when the Mitchell non-arp stud were first
Called out. I got quoted the same price as the whole kit with cross bolts, nuts and washers.

Turns out arp made it difficult to purchase just the studs alone.

So I bought the whole kit instead.

Turns out they changed the cross bolts for cross studs.

I'm not sure I need that but I'll run it.

Just seems odd, like 100 other things.

Darren at KB told me to watch for header clearance issues (good point)

Gee I wonder who could have told him that about the cross bolts? The Indy aluminum blocks are the same way in that it sticks out of the block (not recessed). TTI headers will hit on a hemi for sure....AMHIK...Wedge maybe not. Probably depends on the header tube diameter. I have ARP kits here for that deal that use bolts. Odd.
Todd

Do the studs for the side "bolts" have the allen head to help insert them?
I actually liked the side bolts (flanged bolts) , Stud and nut are just more parts to fall on the floor...
Are they flanged nuts, or do they have washers? more parts for no reason. IMO

Good heads-up on the potential header interference. I have seen some headers touch a windage tray that stuck out slightly from the oil pan rail.

And the oil supply line itself.....You would be surprised, but everything wants to occupy that small space.

That's what I thought as well... "Why do I need all this?"

They do have an allen head, so they're no problem to service. Separate washers and nuts were included
to make it as complex as possible. I have to ask why.

Don't top fuel engines usually have bolts?

Could it have been Bigfoot, or was it Sasquatch?

I tend to think it's a great big world out there but the truth is, it gets smaller everyday and
it probably doesn't help that the Mopar world seems to be shrinking even faster yet.

Yeah I can see how it could get cluttered right there. I'm going to run the oil line similar to the way your buddy's 572
was set up (the one with the 6 pack on it), so that might help a little.

I believe I would just use grade 8 bolts for side bolts. They have worked for 55 years. Anything else seems unnecessary.

Two of the aluminum blocks I used that came with the no name studs ended up needing them replaced.

On one of them they made it through the initial assembly, but several wouldn’t torque up on the first freshen up......... on the other block several wouldn’t torque up on the first attempt.

And that was using the tq spec from the paperwork that came with the block, which was lower than the ARP spec.
The side bolts looked like hardware store grade 8’s.
Junk hardware in a $5000(at the time) block.

The ARP’s higher tq spec required the blocks to be line honed to get the mains round again. Might be more of an issue with the aluminum block, but after replacing the studs, on one block the crank was quite hard to turn, and the other one tuned okay, but didn’t feel “right”........ so they got line honed(just more time and $$$).

If any header clearance issues are encountered I guess I will probably just switch to bolts.

The original mains that came with this one seemed to torque okay, but who knows for how long? Why find out the hard way later.

I noticed the more recent ones (probably old castings) that were recently shipped....did not even have main studs, they had bolts.
The specifics of the fastener type seem to be off Chrysler's radar throughout the history of the product.

The hole in the block is a clearance hole and tapped into the mains and used with a thru bolt.
There is no added advantage to using studs with a nut. IMO
The PSI of the thread in the main caps are the same weather your using a bolt or a stud.
To pull the mains out you would have to remove the stud anyways.
Studs are used to make the thread in a aluminum part a non working thread so to speak,
It's not good to continually take a bolt in and out of aluminum threads.

I have had clearance issues with cross studs.
They hit headers and bottom of solid motor mounts.
Had to sand the studs down so they were flush with the nuts.

The ARP kit comes with torque recommendation of 110 ft-lbs, block instruction says 100 ft-lbs.
When checked with ARP Tech service they recommended to stay with 100 ft-lbs since the block was already prepared for this torque.
110 ft-lbs was the normal torque on studs with the advertised strength.

The ARP tq spec is with recommended ARP lube.

The Mopar TQ spec is for clean and dry threads(as I recall...... no mention of bolt lube at all).
I used a couple of drops of 10/30 oil on the original studs/nuts...... and several of them wouldn’t torque up(the tq wrench never clicked..... the studs yielded).

The net fastener stretch is going to be a fair amount different between 100lbs with a couple of drops of oil vs 110lbs with the ARP lube(if the same fastener was used with both lubes)....... and I def don’t want to under torque the main studs 10ft/lbs, and not provide the correct fastener stretch/load.

As an example of the tq value difference between oil vs ARP lube...... from back when the instruction sheets came with specs for oil or ARP lube....... a 180,000psi 1/2” head bolt had a tq spec of 95lbs with ARP lube....... and 130lbs with 30w oil(35lbs extra to theoretically achieve the same stretch).

Main studs look too short

To me, the cross studs look too long!

Nuts look loose.

Bill Mitchell should have been slapped for doing this, but people keep buying his product.

Have the exact same thing in my dad's World hemi block. The cross studs are kind of a PITA. Threw away the fasteners they came with and had it align honed.

FWIW...the TTI headers on my cuda needed clearancing for the cross BOLTS in my KB block.

kinda hard to put a stud behind the oil pump too