mk1 electrical gremlins - alternator specific (...I think)

[area53 at validpath.com (Jeff Toomasson)]

My grey 81S (thee of the broken alternator tensioner bolt) doesn't get a whole 
lotta love with my project swallowing up every ounce of free time.

I got it pretty much as it stands today w/ the PO having done a lot of the work 
(mostly decent, some not-so). Basically, the car runs what I think is a stock 
style 8v alt (quite possibly a piddly 55A from a non-A/C car), and it has an 
H4/H1 combo (bulb wattage unknown) that is definitely NOT relayed. The car also 
runs a fuel enrichment device that seems to starve under lower voltages (as 
evidenced by the A/F ratio gauge).

ANYWAY - the car has a voltmeter installed and only runs around +12.1V when NO 
accessories are used. Flip on the lights and I'm lucky to get >10V. Suffice it 
to say that the battery is a POS, but I'm not gonna fork out $$ for another 
until I get the damn alternator upgraded or figure out the solution. I do have 
a 90A alt but it's already been installed on my ABA rebuild that was for the 
project. I had hoped it would stay there...My questions are these:

1) Should I be focusing on the grounds instead?

2) How much difference would relaying the lights help?

3) Barring the above two (in the interest of fixing it quickly as it's my DD 
for this week), how much would the 90A alt help?

Thanks a bunch!

JT