[sdiy] Variable Voltage Regulator as replacement?

[John Lamb]

Is it viable to use a 317 type variable voltage regulator as a replacement for a 7808 8v voltage regulator?  
I'm buliding a PAiA Fatman from someone's botched previous attempt and I can't find this part anywhere, 
but I do have the variable regulator.  Also, any links or advice on performing this procedure would be 
much appreciated.

Also, where can I find resources on building a tape delay box?  It doesn't HAVE to be tube-based. ; )

Thanks in advance,
John Lamb