swapping speedo rev counter (clocks)

I was just wondering if i was to put the clocks out of a mk1 scirocco GTi into my '79 golf 'n' is it an easy swap? Will i be able to wire in the additional rev counter easily? at the mo i have a hideous after market rev counter on top of the dash, if i buy a set of proper series 1 GTi clocks will everything plug straight into them?  :dontknow:
Any help much appreciated, as always!!
Cheers
Sam