At minimum they need to be checked for out of round after installing the new bolts and torquing them to spec.

 

I'm not understanding the reasoning here. The ARP bolts are the same size, just stronger, they will be installed at the same torque setting. Why would the rod need to be re-sized? Why would it matter what bolt is in there?

 

I can't answer with 100% accuracy on rods. Probably like main studs, some engines are good without an align hone, some aren't. Kurt Urban once told me that he has seen some blocks that were OK with ARP studs as is, but most needed an align hone. I got lucky on my first LS engine. But my LS7 needed it. Again, this is where the mains are concerned, NOT the rods. FWIW...

 

That may very well be the case. I have seen that happen, albeit years ago. If that happens, there are usually "witness" marks that exist. When you get it apart, check and see if there is a shiny spot on either side of the skirt where the piece cracked off. This would be a "witness." If the piston was dropped, it may have left a slight bulge or burr on the skirt where it deformed. Over time, the spot(s) will polish. Fun to look just for the Hell of it.....

 

The mystery deepens! I've got all the pistons out now and cannot find a missing piece anywhere.
I now believe that the piece was in the pan from another motor, the pan was off when I picked the motor up.
I thought it was from number 1 because that one is a little different looking than the rest.
Here is a pic of the piece and where I thought it was from. It's too big to be from there.

 

Stronger is the key word you used. Because the ARP bolts have a greater clamping force, they have to be torqued to THEIR required number to achieve THEIR required bolt stretch. This in itself puts a greater clamping force on the rods cap causing it to distort. It’s the same with main caps as mentioned above.
Fun fact…the OEM torque value for the TTA GM bolts is 47-48 ft lbs…when using a torque wrench, not an angle indicator…if you torque that same fastener to…say…65 ft lbs, the big end will go out of round and the rod is basically useless at that point unless a .002” oversize bearing for a cracked cap LS rod can be fitted with a light hone of the rod.
What I’m getting at is that torque values dictate a rod or a main bore staying where they were machined at. You can easily overtorque any fastener and mess this up…which is why an ARP rod bolt can and typically will put an OEM cracked cap LS rod out of round.
Another fun fact while I’m at it…I’ve seen headbolts get overtorqued and it take a cylinder out of round, even though the cylinder was honed with a torque plate. Same principal here…headbolts “pull” up on the block material surrounding the cylinder. Every cylinder that gets honed with a torque plate, has the “headbolts” torqued to a certain value. This is a twofold process…ONE is for proper clamping force of the torque plate, enabling the torque plate to do what it’s supposed to do while honing, and that’s to simulate stress on the block from the headbolts pulling up on it, which distorts the cylinder. Two is for the person that assembles the engine to DUPLICATE that torque value so that the exact same forces are applied to the block. This ensures the cylinder stays round.

 

This difference can be ascertained by using a dial bore gauge on the big end of the rods and comparing the measurements of TTA bolts to the ARP bolts correct?

 

Interesting. So, I called ARP and asked that specific question. They said, "As long as you didn't spin a bearing you will be fine". The ARP bolt actually has a lower torque than a stock bolt, 40 vs 48.

 

So that piston on your first post that appeared chipped was an optical illusion or something? Looking at your photos, that chunk does look larger.

So everything was good then? Doh!

I guess since you already tore down the engine, you will have more confidence that ever is good.

I accidentally dropped a piston/rod when I was pushing the pistons out of the bore (learned I need to be more careful!) I had a bit of mushrooming on the edge, which I filed down flush and it didn't get close to ring land, so I sent it. It was just a stock rebuild in my suburban 2500 daily driver. It's been running good.

 

Using your dial bore gauge or a telescoping gauge and a GOOD caliper, mock up the rod with the OEM bolts…torqued to spec…and then mock the rod up with the ARP bolts…torqued to spec…and take good notes before and after. You need to measure out ten-thou to really see the difference here.

 

Yep. looks like it. That one piston just looked worse than the rest.

That is good advice, thank you.

 

OK, next question, pushrods and rockers.
Again, I'm not pushing this motor upwards of 6k or so, are the oem push rods adequate? If aftermarket, which are good? OEM length is 7.385, I don't see that length available, should I go to a 7.375 since I am going with a bigger cam?
Do I need to upgrade the rockers? Just the kit or complete new set? Roller bearings or brass bushing?
This motor has very low run time so I'm re-using a lot of parts. I might just run a year, get everything sorted out and upgrade later. Not planning to run every weekend, maybe twice a month.

 

Many have ran stock rocker arms without replacing the caged needle bearings but if you're getting aggressive on the lift it's best to replace those with CHE bronze bushings or buy a set already made. Anytime you change cam, lifters, rocker arms, different thickness of head gasket or even using milled heads it's going to affect pushtod length. The difference of 0.010 on the pushrod length may not be an issue when most lifters call for +/- 0.010 preload. You can still run 5/16 pushrods and you can even get them with thicker walls so they're a stiffer pushtod. I bought a set of 5/16/ .115 wall thickness from Smith Brothers and a set of TSP steel non-adjustable rollers with the CHE bushings for my 370 build and the camshaft in that car is 238/246 .633 on the intake and exhaust on 111+3 LSA but for what you have for camshaft you can get away with stock rocker arms and a beehive spring and it certainly wouldn't hurt to run a stiffer pushtod.

 

Thanks, I do have better springs to install. I'm going to get that bottom end together this week, and start on the top next.

 

Dang, ran into another issue. Wiseco pro tru street piston kit, wrist pins are .945, but oem are .9431. Pins won't go in. Is this just simply a hone out the rod bushing a little to fit type of thing, like I'm hoping?

 

I'd rather have the rods for the .945 pins but yes you can send them in to be honed.

 

How strong are the oem rods? I was doing a little research and found some people saying that they're weak and aren't often even the same length.
I'm kind of leaning to upgrading rods rather than putting money into something that's less than ideal.
Any better rods available without going crazy on cash? Summit has a set for $400 "not in stock".
I don't know for sure what hp level I'll be at, 365 is oem, with higher compression and the stage 2 cam I'd expect to clear 400, but by how much, who knows.

 

Summit has a set of Eagle SIR I beam rods for $340. 6.100 length, .945 pin, 5140 steel. those should work.

 

Check out the Scat ProComp I-Beam. A little more money but a stronger rod.

 

I don't see a Scat Pro Comp on their 'site, they do have a LS1 Pro Series 4340 forged I-beam with 7/16s ARP bolts that is 6.100, but the pin is .944. Is that the one?

Now I see the ProComp at Summit, pin size is .927.

I sent an email to Scat to see if I can get .945 direct from them.