Can't crack hash of 60 digit pass (only few unknow digits)

[DudeSon]

tldr but can JtR be useful here?
Let me know if the existing formats don't support multi-block. I can write a custom (read slow) format for this job

Thanks for the offer I read opencl-support isn't as good as Hashcat, so I doubt it can handle big passes at usefull speed, I'll surely try it if I can't do it the Hashcat-Way.

The problem with > 55 is that you require another transform. Speeds will at least drop to 50%.

I measured the hashing speed of 54 chars with 3x Amd 58xx cards, it's 180Mhash/s (10chars go at 5 GHash/s) . After some overclocking a 50-70% speed drop to under 90Mhash wouldn't be a big problem I think. (I'll only have like 4*10^12 possible combinations)
Although this feature request has probably no general use for anyone except me, but is there be a way my request could be filled? (some comensation for coding is possible )

EDIT: nevermind