Hey guys, looking at alternators since mine is ancient and or bent now, and the upper bolt hole is stripped, so its seen better days.

Externally regulated 3-wire system, so nothing new and fancy, and dont really see a need to convert it over to a 1-wire at this point.

So really, how many amps do i need for a basic setup, no-AC, no power accessories. Just an MSD 6AL box powering an HEI, and a heater fan/headlights/etc...

There are a lot of fancy alternators out there with a lot of big numbers, but i really dont think i need that much. Any input or guidance would be appreciated. Thanks!

Daniel

Add up all the amperage your car would consume, and buy accordingly. If you don't use anything but your MSD as an addition, Add all the numbers on your fuse block plus your MSD.



Rocky

I hope this helps, A stock 70 B.B. without A/C had a 37 Amp. Alt.
" " With Fac. A/C had a 61 Amp. Alt.
Bob

Both of our cars came with 37 amp 1100837 alternators. I never had a problem mainly because these cars had few options to power. If you are running big stereos and such, you might need more output.

Ok, so the autolite replacement alternator that is down at the local kragen for $50 bucks that puts out 61 amps should be more than adequate for my situation. That is great, i wasn't wanting to spend a ton of money on one if i didn't have to. Leaves more cash to buy the other stuff i need to finally get this thing running.

Daniel

Daniel, You might want to check to see if you need to upgrade the voltage regulator when going from a 37 to 61 amp alternator. You do on a 66, but I don't know if this applies to your 70.

Daniel, You might want to check to see if you need to upgrade the voltage regulator when going from a 37 to 61 amp alternator. You do on a 66, but I don't know if this applies to your 70.
Voltage regulators regulate voltage, not amperage. No need to change the regulator if it functions properly.

I would --never-- install an externally-regulated alternator except in a concours-restoration vehicle which didn't get driven.

In any vehicle where FUNCTION is important, I would convert to an internally-regulated alternator because of the increased idle and low-speed output. Conversion is incredibly simple, and the internally-regulated 10SI or 12SI alternators are not particularly expensive.