[MadHippo]

is it worth paying for the main stud kit as opposed to using bolts? what are the pros and cons?

[quick67bird]

Originally Posted by MadHippo

is it worth paying for the main stud kit as opposed to using bolts? what are the pros and cons?

Depends on your application. The studs have a better clamping force, but if it is not a serious race engine I would not worry about it. If you get studs you will have to have the line bore checked and possibly linebored and honed.

Robert

[P@blo]

Think it goes like this:

Under 500 horse 2 bolt caps with bolts
500 + horse use 4 bolt caps with bolts
700 horse and over are stud territory

I found that in an older post from Mr P body so I hope that helps as studs might be a waste at a certain power level.

[bastereo]

where do 2 bolt mains with studs fall in on the power capabilities?

[krisr]

They fall into the piece of mind power capabilities.

Also it's not a requirement for a linehone if fitting studs, but always prefit the caps/studs and check for round before assembly. My 2bolt 389 took studs just fine without a linehone/bore.

[Half-Inch Stud]

Steel Caps are mandatory for the 455 Journal in drag dress.

Outer bolts ougth to remain Factory Bolts in all applications.

Inner bolts are my preference in all applications, yet folks here sleep better with Studded Inners.

Thought I saw a busted main photo herein that shows the Block will let go before the Steel Cap or Studs let go. I bet Factory Bolts would have also hung-in-there.

I bet further that the Bolts will torque to a design-centered value with stretch, while the STUDS will not stretch, thus ALLOWING a Main web to bust-out earlier.
--------------------------------------------------------------------------
When you use those Main STUDS, You got to ask youself 2 questions:
1. what torque level are you going to Ft-Lb the Nut to?
2. Is the tension from the Fine-thread nut-pitch causing more tension on the coarse Web-thread.
=============================================

You see, I don't remember the pitch-ramp difference for Coarse-to-fine thread.
Do you remember?
Well, do you?
Do you feel lucky MadHippo?, well, do ya? -Eastwood HIS

[PMD428]

I did use ARP studs on my 428 4 bolt. This was more of a peace of mind thing for later on if I wanted to add more power. I did have to have the mains honed because of this.
we will see soon, another 3 weeks before dyno time.

[MadHippo]

thanks all. I decided to stick with bolts after I finally found some from Pdude. I think Ill sleep ok, and yes, i do feel lucky . After the motor blows up, I'll post pics here.

[Jack Gifford]

Since H.I.S. doesn't remember (or pretends not to?)-
Front four mains studs are 1/2-13 bottom, 1/2-20 top.
Rear main studs are 9/16-12 bottom, 9/16-18 top.
('bottom' & 'top' as seen with block upside-down on engine stand)

[Junkyard Dog]

What if choice is limited to two bolts or two studs, and power is just shy of 600/600 (or maybe just over)?

[BVR421]

If we are talking about the usual warmed up 400-455 with 2 bolt factory main caps, I will take 40 yr old factory main bolts over ARPs gimmicks anyday.
If you are going 600hp+ with a factory block and iron crank its only a matter of time anyway regardless of expensive steel caps and studs. They _might_ help it hold for a while.
On street motors I reuse the old rod bolts on factory rods with new Pioneer nuts.
Just one more opinion.

[Junkyard Dog]

BVR421, are you suggesting reusing the main bolts on a two bolt main cap for 600 horsepower?

[Half-Inch Stud]

Here's a Half-Inch GUIDELINE:

Factory blocks: Factory Main Bolts marked with 5 or 6 slashs.

MR1, IA1, IA2, others: Either Bolts or Studs on Inners. Factory Bolts on Outers.