A nieghbor of mine has a 1978 30' Welcraft Scarab with trs drives and I believe Merc transmissions that are electric shift???? I can'nt find any info or drawings of this trans. Is it the same as the manual shift trans and can it be rebuilt to accept manual cable set up ? One of the units does not work ? who can rebuild them ?

You can either rebuild the electric set up of you can swap it all over to Manual. I personally like the manual as it shifts faster. When you ask who can rebuild them do you mean the electric shift motor or the tranny? If you mean the electric shift motor any alternator rebuild place should be able to take care of that for you. If you mean the tranny then I would say either Bam or Huber can take care of that and even offer upgrades.

Jon