Last stock block I broke...........the first thing to go was the block itself. Noticed an oil pressure fluctuation and pulled the motor to have a look. Caps(alum) fine, crank fine......block broke all to hell in the webs.

Many want to blame it on detonation and say if you keep it out of detonation, it will be fine........No it won't. It's about the power level. Now, detonation WILL hammer a motor, but if it is hard enough to break caps and blocks, you will also see that amount in other areas.

As somebody else said.......these are 40 year old passenger car blocks. They were NEVER engineered to be all out race motors, at the power levels that can be easily attained these days.

At a significant power level, a stock block is a crap shoot. It might last one pass, ten passes, hundred passes, thousand passes...........you simply never know

I have managed to split one ([censored] my names AL as well), all my fault with a lean nitrous tune, 528, steel caps with girdle running 9.2/9.3 @ 144 in a 3500lb 63 Maxi Plymouth.
You live and learn, I have not run nitrous since but then again Im not drag racing at the moment either, I do beat crap out of my NA engines at events and the street.
I now have ali caps in the 528 and steel in a spare 547, girdle not being used.

I went with a slightly different girdle system on this engine. A lowdeck 3.900" stroke deal. Made 780hp with a fairly big roller. J.Rob

My old 505 engine was cracked when we pulled it apart. The engine was running fine but after 100+ dyno pulls we decided to pull it apart and look over everything. Several of the main webs had visible cracks. I just took the parts and moved them to another 440 block.

Andy's story should bear a little weight. This is a dyno mule. Probably NEVER mistreated, run lean, had the snot beat out of it, or anything else. But it made a good bit of power and even with it's relatively easy life, it beat the webs out...............Make power, they break eventually. It's really that simple. EVERYTHING breaks eventually, it just depends on what life span you expect............We beat the main webs completely out of a $6000 Donovan alum block after 5 years. But it had no telling how many passes, pushing 2000hp through it.

I have always been a proponent of the aluminum cap method, as well as alum rods and a light rotating assy. Not because it "fixes" anything, but because I think this is the cheapest and most effective "bandaid" for the situation. I think the alum caps absorb some of the beating, as well as the rods. You also have lower initial cost investment and machining vs girdles, pro-gram caps, or about anything else. So as we have pretty much covered, NOTHING is going to "fix" the problem, so choose the method you think is the best and that you are willing to pay for.........but you also need to accept the fact that whatever method you choose, it will likely fail at some point

I have been lucky but stopped pushing my luck and bought an alum. block.