Help me Pick out a New Alternator

[78 K-10]

Hey guys,
So Its been a while since I was on here, mainly due to the fact that my truck has been running pretty sweet for the last year or two.

I've been buckling down on my classes and will be getting my degree in 4 months for "Network and System Administration".

I'm super stoked guys because when I get my first job I will make more money than I ever have before and you know where some of that dough is going, yep, chevy trucks.

For now, I just want my baby to run.

So a little back story. My belts are both 2 years old. I have 2 amps, 4 speakers, one 10" sub and a new head unit. The rms power for my sub and amp are both 150 watts wired at a lower resistance of 2 ohms rather than 4. Its a "power efficient" system but its tuned so nicely and cranks so loud that I assume my stock (most likely original) 63 amp alternator and old brittle 14-18 gauge wire just doesn't cut it. Everything is original in my truck and in fairly good shape due to the fact that I bought this bad boy about 4 years ago from a guy who had it in a garage since 1985. Original paint... blah blah. Oh, wait, there is a lot of stuff that isn't original too, stuff I've replaced.

A month ago I was driving to a job, going 50 in third gear and I noticed my voltage gauge drop from its usual position of around 14 to below the half way mark. I immediately shut off my driving lights, heater, and stereo. That help a little and I made it to work no problem. When I got home I opened the hood and assumed by belts were loose or old so I tightened my alternator belt to about a half inch of play, nice'n'snug but not too tight. I fired her up and boom! voltage was back up to normal. Before this I had noticed a slight hum when I turned my lights on during colder days. So all was well, bumpin my system for the next 2 months.

I was working on my orchard a couple days ago and since I have a Optima Red Top I decided to play my stereo loud enough to echo throughout the entire orchard, (about 200 trees )

I have played my music like this many times for about an hour during summer and now during winter. Only this time after a while of playing music I started my truck to recharge my battery and it was way below half way and never got any better...

The next day I tested my batter and yes it was pretty drained at 12.01. I threw it on the charger for 24 hours at 12v 2 amps (trickle charge)

Taking the battery off the charger it read 12.89. Perfect! not overcharged and the next day it read the same 12.89 after I reconnected it to my truck. So clearly I don't have a vampiric drain of power somewhere.

truck cranks over just fine, runs smooth

after starting the truck, the battery stayed between 12.46-12.50

I then took my alternator to NAPA and had it bench tested. The guy let me go back with him and the tester has 4 criteria it tests. I saw it pass the first 3 criteria and the 4th it had a red FAIL. This last fail was the conversion of AC current to DC current. AI am pretty sure it is the bridge rectifier that went out. Through my research I am pretty sure it is responsible for this AC->DC conversion.

My questions are:

1. what amperage alternator should I get? (I was thinking 100-140)
2. Which brand is the best? (I only buy MADE IN AMERICA)
3. Are some brands better at providing better amperage at slower rates I.E. during idle? (considering my system)
4. Besides re-winding, is there any way to rebuild my alternator with a higher amperage?

The one thing I have always avoided is electrical stuff. So if anyone has any advice I am all ears.

I went to Napa yesterday and got a bunch of 0 gauge welding wire and some ring terminals and will be upgrading all my grounds. While I was cleaning up grounding points, I was laughing how the original ground wires are the size of spaghetti and my new ones are the size of my garden hose...

thanks guys.

 

[78 K-10]

I'll be down in the shop tinkering with her.

I'll check back every hour or so.

 

[Stroked]

I had a Powermaster 140 amp alternator on my '86 K10 back in high school and loved it. Other than that, I've only ran the stockers.

 

[bucket]

I've always run stockers too. My "upgraded" ones are just higher amp models meant for other GM products.

 

[89Suburban]

That music in the orchard part made me laugh, thanks.

 

[dhamp]

Somebody else chime in if I'm wrong, but you only have about 25A of amplifier load. Even with the head unit, stock accessories, and headlights, I'd think a stock replacement would suffice unless you're planning something more radical. The little Mazda 626 I had in college only had a 65A stock alternator in it and I was running one Kenwood amp that was 200w RMS/ 380w peak and another Pioneer amp that was 120w RMS/180w peak. The car was 17 years old when I sold it and still had the original alternator was still on it.

 

[78 K-10]

I thought I read somewhere that alternators only really put out around half their potential at idle. So my 63 amp, if it is "ON" will only be putting out around 30.

If I did go with my stock amp, where could I get an OEM rebuild kit or which rebuild kits are the best?

Also, I noticed a small fuel leak coming out from my Rochester Quadrajet. Its dripping from the connection where the little paper fuel filter is in-between the carb and the fuel line. If it is stripped what do I do since the female part of the thread is the actual horn of the carb.

One guy recommended Teflon tape. Like white plumbers tape you use on the threads of plumbing?

The alternator number is 1102854 63 A 7C 4-12VNE