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Hey Fred , I had seen this before, I like the closing statement that anything under 1.6 ratio is considered a design screw up, I guess its stuff like this that keeps me asking questions with my 1.54 ratio, it seems that if ya shorten the compression height most skirts get shorter putting more load on the major thrust per area but with less angle force from a longer rod, who knows for sure what the forces are when you start changin things around

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I have been running 6.125 chevy rods in most all of
my stuff... the currant 405ci W-9 has a 6.125 rod
on a 3.79 crank in a 9.200 deck block... my CP pistons
are real short and the pin is in the oils ring area,
been turning 8200 rpm since day 1. I use to pull it
apart every year to check for wear... now days it
hasnt been apart in a couple of years... I still do
a leak check every once in a while during the season.
BTW, its been alot higher than 8200 rpm but I didnt
make any more power(needs more cam)

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Thankx Mike, your running a better block than the one we are foolin with , When I get the sonic #s back I will know what I have to work with, I was thinking of dropin back .020 on bore size to 4.040 to try to keep more meat on the walls and this whole rod thing is up in the air till it makes sense to me

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I used the same rods and crank in my production block
396 ci.... still turned 8200 (same as in length and
stroke)

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What wall thickness on major thrust were you running with around what bob weight?

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I dont recall... its my W-2 engine thats my back up.
It's a .030 over bore and the bob was in the range of
1800 (I think)... been a while since I built that one,
it ran my car 9.56