It seems I was wrong about the cause of failure.  I was thinking tension failure.  Yet again, I learn something from your channel.  Thanks!

50 years ago, it was generally accepted that the max rpm for 400's with the stock rods was 6000, and the 455 was limited to 5500. That was it, and when we stayed below those limits we never had an issue. Not many stock Pontiacs made more power there anyway, you were generally beating a dead horse past 5600rpm with the 400's, 5200 with the longer stroke engines. The oil pumps with the sheet metal bottom plate were a bigger problem than the rods, they would develop a gap between the pump body, and leak oil pressure right there at the pump. The thicker cast cover was always the way to go

This will be a fun one to watch. I bought a 1968 GTO drag race car when I was in grad school back in 1994 for next to nothing because the transmission was split in half. It had a Pontiac 400 with unknown specs but once I put a new transmission in it the thing would pull the front wheels off the ground. Scared me so much I sold it LOL. Thanks Alan!

I love a good necropsy. A very powerful learning tool 😊👍. Thanks for the vid!

Another good informative video Allen

I remember vividly as a young kid listening to an old timer scolding a guy about over revving his new 409 chev...that left an impression on me I've never forgotten.

Good information! Subscribed. Thank you!

Big heavy parts make their own exit when they want

Good video, AG. Thanks!

hope to see it on the dyno.

High rpm is the main culprit in positive crankcase ventilation.

I remember reading about poncho rods in car craft, max rpm 5500.

Alan, good diagnostic failure information and advice! 👍👍 Bob

You should ask Canadian Tire/ Mastercraft a sponsorship deal. If they refuse, you should hide their names from your toolboxes because we see them a lot. So far, it’s free publicity for them.

A pretty scary situation when you open an engine bottom and see stuff like what was found in this engine such as rods still in 1 piece or should I say normal 2 piece with a missing rod bolt yet still on the crank in an area that didn't breach the catastrophic level as the front region did. I've seen several engines with similar issue, all or most of the damage at the point furthest from the oil pump. I feel that the engineers designing these engines did their diligence homework. Engines in R&D were put to the limits to see what would happen under specific conditions and when failures were experienced, they either decided the condition which caused the failure was not was not within the range of operation the engine was being designed for. If the failure was a normal occurrence during developmental testing, that part was sent back to the drawing board and modified to reduce failures. It happens all the time and now it seems to be happening more to owners because factories and engineers are not in designing engines like they used to by spending years testing for failure rates and causes like they did 30+!years ago. They come out with something that looks good on paper but in reality doesn't measure up, costs more to test and hold back in releasing until the design is proven to be quality. The bar for standards has been lowered to cut production costs and sell a design that is supposed to meet upcoming regulations instead of quality expectations!

Great channel, appreciate your time that you share. It’s a great time to be a  car nut, decent quality (forged) stroker rotating assemblies are available for Pontiacs, Olds etc allowing us to create really usable fun engines for sorta reasonable money.

Absolutely. You can buy a complete aftermarket recip assm and have it in days. Rebuilding is important if you are building a numbers matching engine for restoring purposes but for hot rodding not so much anymore.

I remember back in the early 80's as a kid my neighbour had a 455 Trans Am and he was always blowing that thing up because he drove it hard. People with the 440's never had that problem or the 454's. Trees and ditches killed those engines lol.

If you are getting your rods reconditioned, it's always a good idea to get them shot-peened as well, especially if you are upping the power.

Mahle makes a powerpak piston for the Pontiac. Metric ring pack, weighs 529 grams. For a 4.155” bore, 4.25” stroke, 6.8” rod. Flat top 6.4cc valve reliefs.