Like I said, we have a tone of them running around here. The guys I race with all have them. The 440/512 is a power house and the most popular, and we recently built a 440/526 and a 400/512 with the light weight crank option. If you can keep the rpm in check, life is good. I personally have nearly 1000 documented passes on my old 440/512 combo.

I would love to build one of these with a good after market block someday.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk