I totally agree aside from the case with the LA block in the front ! Which is one of many reasons, main girdles came about in the first place. Then there is the famous SBC where they only gave use 4 bolt mains in the center 3, go figure, BBC has 4 bolts on all 5 in the 4 bolt version. It's been too many years since I last saw a Pontiac Super Duty with 4 bolt mains so I can't make statement here. We all know that technology usually moves forward as in the case of the newer engines like the 4.7, 3.7, 5.7 and LS blocks and tritons along with the wonderful little GM 3800 all with cross bolted mains. There are many others with this added engineering, Nothing much anyone can do with the old LA front upper region with all that iron drilled out for oil passages though. No main girdle is going to help cracking with those engines. But on the topic, the mains do have webbing and support in the center and with the block basically made triangular in design, double wall if you take into account the cylinder walls and water jackets, there is a lot of iron or aluminum to have to flex. Now looking at a 4.7 a very nicely engineered engine, a little help from Mercedes there, with a full lower block support arrangement, well technology absolutely improved ahead there, to bad it went lightweight everywhere else. I dont like fractured forged powered rods as much as fully forged steel although they do well to hold bearing inserts from scuffing and loosing preload. If you want to see an engine that is really built to eliminate issues in crank support just look at a Kubota. No free mounted main caps as with most engines, bearings are mounted in a split circular support which slides in from the end of the block as an assembly then bolted 90 degrees from the bolts that hold the bearing retainers together around the mains. If someone would take this design and incorporate it into something we could and would build for high perf. blocks that can be fitted to something like an A,B,E forget the old F bodies, that the fenders come up in the back if bounced hard because of how the torsion bars where designed, or any other popular offering from any of the makes of muscle cars.
