I love the LSx based push rod motor.. but seriously..
Until I see the dyno charts and time sheets for the run - I think we might chalk this up to a "fishing story"..
It may FLOW 658hp worth of fuel mixture - but on pump gas and without a power adder at stock displacement and not running super strong valve train so it can spin to 7500rpm+ - he is not putting 658hp out of that motor..
The most agressive cams and high comp LSx stock displacement motors will give about 525 crank hp without a power adder..
Anyone actually have the full article so we can see the low down on this engine? Dyno charts etc?
My guess is that this motor sounds like many of the heads/cam motors around these parts and puts about 460rwhp (525+- crank HP)
I would love to believe that he has a 550rwhp stock displacement LSx engine.. but I dunno so much..