This really saves on buying an X or R block.

People should not confuse themselves into thinking a oem block can even come close to what a X or R is or can take.

The main webs, the filled inner pan rails, the thicker decks, cylinder wall thickness. The nickle content.

From side by side on a stand compassion to parts attrition on freshen up its all easily spotted.

The main reason we see x or r blocks in these times that cant go 4.100 safe is because they are seconds from the days when they were easy to get and were set aside from core shift as culls.


Absolutely. There isn't a production block out there, other than a T/A block that should be considered for serious power. The main line will flex like jack the bear so you need to run looser main clearances, the decks are too damn thin for boost (IMHO) and putting 4 bolt caps on ANY production block is a desperate act. In fact, I won't do it. There isn't enough material there, even if you use a 5/16 bolt and it's offset. Isn't worth it as the support isn't there.

AFAIK there is ZERO difference in the cast iron used between LA blocks and magnum blocks. They hone the exact same. They are both harder than a Ford and significantly harder than a Chevy, but they ain't an X or an R block and you'd know it as soon as you hone one.

Other than lack of availability there is no reason to use a production block in a serious power application unless you just can't get something.