Originally Posted by 1Bear

I know everyone knows that there are differences in the bolts and that the more expensive versions are also in this case stronger, but I’m wondering if most folks are just setting back and reading the tensile strength of the bolts and trying to determine what that means to them. While just about any of the aftermarket bolts available, including the lowest grade from ARP will work for probably 95% of us, actually the factory bolts from 2000 and up will also work reliably in most of the street builds that are still using stock rods, but given the price difference for the basic ARP bolts there is no reason not to upgrade. Upgrading the rod bolts never hurts a thing as long as they are installed properly and the rods are not distorted from the installation. However does it really do any good for the motor or your wallet to have bolts that are capable of handling a 1000hp or more, when rods are really only good to about 450hp or so. Yes some have pushed parts in their motors well past the recommended ratings, but were talking about being safe here. Typical entry level I Beam rods with basic ARP 8740 bolts which are also generally larger in diameter than the stock pieces will have somewhere around a 600hp rating and some high end I Beam rods with ARP 2000 bolts may handle 1000hp or more. While a good deal of the additional strength comes from the larger bolts most aftermarket rods are equipped with, typically 7/16” vs 9mm stock rod bolts, you can get sort of an idea of an range of what the bolts can safely handle. You just need to remember that rod bolts or even the rods themselves are note rated by HP and it’s the load they see that kill them.

Stock 2000 + or GMPP = 450HP or so
ARP 8740 180,000 w/7/16” bolts = 700 to 750HP
ARP 2000 220,000 psi tensile w/7/16” bolts = 900 to 1500HP
Katech H-11 260,000 psi tensile 9mm

Per Katech, their bolts were actually engineered for replacements in the GM ASA series race motors and are advertised as being the best you can get and fitting production connecting rods without having to re-hone them to size

I didn’t really say anything with all that writing other than to give some opinions and insight into the strengths of the bolts, but so much depends on the usage (rpm) of the motor, whether or not your still using stock rods or not and ultimately the size of the bolts and whether or not they were installed correctly.

I do believe the ARP 8740 bolts are all you need as long as you’re basically freshening it up and sticking with the stock rods. Due to the fact you’re going to have your motor apart during this operation, it would be a good thing to have your rods checked for size and roundness after installing the new bolts, not to mention having them mag’d for cracks before even attempting to use them. In your case there really isn’t any reason not to.

Originally Posted by budhayes3

Thanks Jarrod, good useful information as always. What rod bolts would you recommend on a build like mine? (NA LQ9, still not sure if they're the early rods or not, WCCH StageII heads, 224 or 220ish cam, no nitrous). Any need for upgrading the rods? I think that combo should yield about 475-500 crank hp, going by the other combos that I've seen, and what TrickFlow claims with their head/cam combos that are similar. Eventually, far down the road, I'd like to do a FAST LXrt intake,...

Originally Posted by fastnblu

You never mentioned how much the Katech's are rated too. I don't think those ARP2000's will support the power I'm after.
Jarrod, Billy wanted your thoughts as to if he should upgrade his rods too? (see below quote of his).



Ya know, good rods often come w/. good bolts. And no, I'm not talkin Carrillos. If you're gettin those, you're b.s.'g on what your plans are & you'll never finish that 6L. While u may require a rebalance. Throw some Lunati, Howard's, Crower or even some Scat's on the lower end. You already aren't gonna DD it, so get a matched Mahle or Diamond (ya, others are good stuff too) piston set too. Do some side jobs. You're not married anymore, so, you'll have $.

Originally Posted by fastrt

I tried to leave the sleeve in, and put the arp bolt in, and it didnt feel right/or it wouldnt go in. I can remember. but if you dont stretch the bolt, it would stretch after you put it in, and you could spin a bearing or worse.

Originally Posted by 1969x11

...Yeah several builds. Cheap insurance in my opinion. I also used their flywheel and pressure plate bolts in both of my T56 vehicles.

Originally Posted by budhayes3

If I start changing the rotating assembly, I'll never work up the scratch for this build...I have to stick my head under my engine (which is on a cradle, on the floor under a bench at my dad's shop), and see if I have the stronger LQ9 rods, which with my luck I don't. But if I do, the rotating assy is staying as is, with just some upgraded rod bolts. If I don't have the stronger rods, not sure what I'll do...I like to know that I have the best gear (within financial reason), even if I don't need it...just like to know it's there ...

Originally Posted by fastnblu

I thought I read or someone told me leavin that sleeve in may be a possible reason for twisted / damaged rods. IDK if u mentioned it before, so if u have, just a brief answer would suffice. But how do u stretch a rod bolt?



Even tho I didn't use ARP bolts for my flexplate, I Loctited the **** outta em. As in put it on a lot of the threads. After I did the install, I read on here where someone said u only need just a dab on bolts' threads. Now, I'm hoping if I ever have to remove them, they're not cemented in & don't wanna come out.



I said that. I I also agree w/. the other hi-lited part.