AND you really should do more than that.
Read this MAD article which is where the diagram above came from:
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
There is SEVERAL areas of concern, ESPECIALLY if you go to a much larger output alternator, and / or start adding hi current accessories, like halogen headlights, big stereo, pump, and electric fans, etc.
First the bulkhead connector ALWAYS has been a problem. Pretending it is not is silly. Some time ago, "we" dug up a discussion that showed police/ taxi/ fleet cars had ?dealer? modified wiring so that the large charging/ battery feed BYPASSED the bulkhead connector, so this has been a problem for a LONG period of time.
"Back in" the day, my 70 RR ruined the bulkhead connector from too much heat and current I reamed it out, and ran larger conductors right through the connector
The areas are:
Too small charging / battery feed conductors
The bulkhead connector terminals were NEVER designed for that kind of current
The ammeter itself can be a problem, as the studs are not really connected to the "shunt" in the ammeter, and in the pickup type later ammeter shown at MAD, it is WORSE, as the "whole thing" is held together against the PLASTIC cluster housing, so when it gets WARM it gets LOOSE, and then it gets LOOSER because it gets HOTTER.
I have personally seen several vans/ pickups that looked EXACTLY like that photo. Some of them were pu's with electric/ hydraulic snow plow systems.