1978 engine in a 1975 spider questions

[Surfbeamer]

I am installing a 1978 engine in a 1975 spider. I will pick up the 75 spider next week have a couple of questions on the swap:

1) I want to use the 78's mechanical fuel pump. Can i just unplug the electrical fuel pump or do I need to bypass the fuel line?
2) would having both pumps over pressurizing carb?
3) I understand that the 78 alternator has an internal regulator and the 75 has an external regulator. If I use the 78 alternator, do I need to connect the 2 wires from the external regulator and piggy back them together? I see on the wiring diagram an orange wire to the regulator and a gray one from the regulator to the alternator.

Thanks for your advice.

[So Cal Mark]

if you use the mechanical pump only, bypass the fuel line around the electric pump.
If you use the 78 alternator, bypass the external regulator

[vandor]

My personal site below has a section on how to wire the internally regulated alternator.

[Surfbeamer]

Thanks for the info.
Does this sound right for the power wires: My plan is to bolt the 3 black power wire together, insulate them and fix them to the right side of engine bay, the side the original alternator was. Then add a new heavy gauge black wire from the starter to the alternator on the left side of engine. In my mind this seems to be the same as running a new wire from the 3 black wire terminations around the engine bay to the alternator, since the alternator and starter are in series. Also, the 1975 wiring diagram shows one black wire goes directly from alternator to starter, nothing inbetween. Let me know if this is right.
Thanks

[BEEK]

you can send the leads that attach to the power terminal of the alternator directly to the starter. check your original wiring, you will find that that is exactly what one of them does. the early spiders have a connection in the starter wiring, i suggest removing that connector. it tends to corrode and cause a poor connection, and can burn up / melt too. then run a heavy guage wire from the alternator positive terminal directly to the starter. you need to be sure that the alternator you are using field does not stay energized after the car is turned off. some alternators that are adapted with a 1 wire setup keep the field energized when the car is off, therfore killing your battery

[Surfbeamer]

I think I hate electrical work because of the terminology
You suggest sending the 3 black power wires to the starter but they are on the wrong side of the engine, wrapped in the original harness and are not going anywhere.
My though is to connect the 3 black wires together, insulate and leave them where they are. Then add a new jump wire from starter to alternator on the left side of engine. One of the 3 black wires is pre-routed to the starter, so essentially this is connecting the 3 black wires to the alternator. I guess the issue is can the existing black wire to starter carry the load of the 3 wires from alternator. If not then should I run 1 large gauge wire from the 3 black wires around the engine bay to the new alternator. Then I dont need to add a wire between starter and alternator, cause one of the 3 black wires already gors to alternator.
If im still confusing things, i will post a sketch later.
Thanks