Amp Meter ByPass
The issue has always been that the factory design sends the bulk of the charging current through the bulkhead connector and up through the ameter. You can do the fleet upgrade and beef up the components to alleviate the issue especially if you really want to keep the stock ameter functional (ie - restoration etc). But since your gonna run a 140amp alternator I'm assuming your gonna run a volt meter. If that's the case, the easiest way to take the load off the bulkhead is to run a piece of wire with a fusible link directly from the starter relay lug to the alternator post. It's what I've done on all my cars. I just rewired my Duster with an engine harness from Bill Evans and did this while I was at it and wrapped it all together, looks clean, super easy and no more ameter issues.
Lastly begs the question, why are you running that big an alternator?? Unless your running ALot of extra stuff (ie- elec fuel pump, big stereo system, elec water pump, elec cooling fans etc etc) then you really don't need it! I've got a stock replacement Autozone special 65amp alt and it handles everything just fine.
Lastly highly recommend Rob (aka Crackedback) headlight relay conversion! He sells a kit that puts the headlights on relays and really helps brighten up all the lights including dash lights etc and further help take load off the charging circuit!
Just my long winded .02 cents