I've got a 180k mile LT1 that's running great but I'd like to get the crank polished, install new bearings (King XP?), ARP rod bolts, and possibly high volume oil pump. Basically, before I start on any top end mods I want to give the bottom end a fighting chance.

I understand that changing the rod bolts will necessitate resizing the rods. Locally that costs $175, the bolts cost $85ish, so the reconditioned factory rods with new ARP bolts would be $260, which is roughly the price of brand new aftermarket rods that already have ARP bolts. It seems like a no brainer to get the new rods... except for balancing.

Replacing the rods with aftermarket ones such as Scat Pro Stock I Beams, for example, would necessitate having the rotating assembly balanced, correct?

Does installing ARP bolts in the original rods also necessitate balancing?

Balancing costs $312.50 locally, so if it's not necessary when reusing the stock rods with the ARP bolts, then that becomes the more attractive option.

Also, would you be confident that an LT1 with ARP rod bolts, freshly polished crank, fresh bearings set up with .0028-.003 clearance and a high volume pump running 5w-30 synthetic (mobile 1 currently) would survive regular track use shifting at 6500rpm?

This is a 94 LT1 which I believe means it has the traditional forged rods, not the later PM rods if that makes any difference.

 

The one thing I can tell you is to skip the HV oil pump. Use a SV pump with a 70# pressure spring. ex. Melling 10554 vintage..

 

Thanks. Do you have any thoughts about the rods/bolt?

 

If you change anything in the rotating assembly it's quite likely going to be out of balance. You might get away with replacing oem with oem, but going to a different manufacturer and design all together you definitely will need a balance job.

 

Are you saying ARP bolts are a different design altogether than the GM bolts?

 

No money spent on balancing is bad..

 

ARP bolts are much stronger than any OEM bolt. To have that much strength they will be made out of a different alloy, which in turn would make them weigh differently. Plus their could be subtle changes in dimensions. For example the bolt head could be a little taller/shorter, threads cut slightly longer, etc. Since balancing tolerances are measured in grams(which is a small unit of measure) these differences will be significant when revving at 6000rpm.

 

IMHO, get the rotating assembly balanced if resizing stock rods with new ARP bolts

 

​​​​​​​Very good everyone, I won't skip balancing. That means it becomes equally cost effective to just replace the rods instead of having the originals resized.

​​​​​​​I appreciate all the responses!

 

Good idea...if you didn't do it....it would be VERY time consuming and cost $ to deal with it after starting motor. FWIW I sent a flywheel to a balance shop (brand new sold as neutral balance) which was 25 grams off due to 4 VERY tiny threaded holes in it for a counterweight a neutral balanced FW would not use. Needless to say the motor would have vibrated like a dog shiating razor blades.

 

Go internally balanced. That way your flex plate/flywheel can be zero balanced separately if it ever has to be replaced.