[oldman]

For a DD, my general guidelines are 100K miles with minimum maintenance, drive like I stole it, less than 10% chance of critical failure. As an example, I'm on my 3rd set of rear tires in 16K miles. I don't "burn out", this wear is all from WOT thru the gears. I estimate I've done 1000 thru the gear runs, and 4000+ 1, 2nd, 3rd blast.

I know for sure that my stage 1 cam should have: new trunions and pushrods now, and every 20K I should check and / or just replace the valve springs. Call me paranoid but I lived thru the LS1 valvetrain issues, don't want to repeat them here.

Given my expectations, under the conditions listed, I would say the stock short block is marginal even at my 7 PSI build (low boost but a fully modified engine in terms of air movement). 600 WHP (about).

Same would go if I want the stage 0+ to stage 1- NA route. 6800 RPM, a VVT compatible cam, ported heads, maybe something like the OEM LS7 spring, I would say is the limit for the short block for my above DD. For a stage 1+ or bigger cam say to stage 2, 7000 to 7200 RPM, I'd change the rod bolts. For stage 2+ to stage 3, I would only consider a fully forged and blueprinted short bock. I'm also sure the vast majority of people out there with stage 2+ cams are on the factory short block 7000 + with NO issues.... for me I would at least do the rod bolts, probably because labor is free to me and they are not that hard to change.

Yes very conservative. But I've been building and driving street cars for a long time. A factory powdered metal rod is not something I'd put over 700 WHP on, and even there I honestly think it WILL have a higher that 10% failure rate over 100K miles the way I drive.... I know I should just get a stock ZL1 and have Chevy provide me the warranty... LOL

[ZNix]

Originally Posted by oldman

Same would go if I want the stage 0+ to stage 1- NA route. 6800 RPM, a VVT compatible cam, ported heads, maybe something like the OEM LS7 spring, I would say is the limit for the short block for my above DD. For a stage 1+ or bigger cam say to stage 2, 7000 to 7200 RPM, I'd change the rod bolts. For stage 2+ to stage 3, I would only consider a fully forged and blueprinted short bock. I'm also sure the vast majority of people out there with stage 2+ cams are on the factory short block 7000 + with NO issues.... for me I would at least do the rod bolts, probably because labor is free to me and they are not that hard to change.

You won't have a problem with the stock rod bolts. No reason these motors couldn't live at 7500 for a long time.

[oldman]

and hence we all have our own builds. I would only consider a fully blueprinted forged component short block for 7500 RPM, and would even look into a LS7 crank / rod combo. Same goes for the powdered metal rods at 700 WHP. I was thinking I'm OK, but now would do the full piston / rod combo. This is what GPI says:
We have found LTI connecting rods during engine upgrades on stock forced induction engines which were slightly bent even though they were still asymptomatic.

Of course they are in the market to sell stuff. We do know the LT4 rod is stronger and the LT4 piston is a LOT stronger. For $1700 to $2500 vs $1200 for just pistons, I think I would go with a full rod / piston combo for anything over 600 WHP, down from my 707 WHP thought process a few months back.