Bigger pulley on alt = less voltage
You want smaller alt pulley

Ive got the March 3pc alum pulleys. Gone through a few batteries over the years. Think they went to press on water pump pulleys in 98 IIRC so only 2pc pulleys available for that or newer model years.
3pc alum pulleys gave my Indy .12 off 1/4m ets. Added them when it only had 14x2.25" open fipk & Eddy TES hdrs (3.55grs). Decent enough gain, just have to pay attention to voltage at redlights if running the tunes loudly, or ac/heat & hdlights.

 

Goodyear Gatorback belt # 4070950 which is a 7 rib belt at 95" long. It is a little more expensive than the stock belt at Autozone but it fit real nice.

 

If you have March 3pc pulleys, do not try running a Gatorback. Belt is thicker & will rub on itself. One time I tried one when experimenting with various acc. bypasses (1, 2 & 3 acc. bypassed) I fired it up & it sounded like I had a blower under the hood even though I was na at the time. Lost all the gatorback off the belt and was left with what looked like a regular ribbed belt. Made a hellova mess under the hood.

 

good info indy

also there is a Gates belt # K060945 which is a 6 rib belt 94.5" long for applications with just the crankshaft pulley.

 

Ahh, I might just try the crankshaft pulley or do both with the crankshaft and alternator pulley. So I would be looking for about a 95" belt with both and a 94.5 with just the crankshaft pulley then? Thanks again guys!

 

I ment amps. on the alt. not the size of the pully. Wouldnt a bigger alt solve the issue?

 

Sorry, my mistake(on nights/tired eyes lol), higher amp alt would help that situation.

 

I had to resurrect this thread. I have the 3 piece March set. I am getting the parts together for this swap.

Just checking, but this is what i am getting (I have the 5.9):

1. Harmonic dampener: I was told to get this from Billy at KRC, he used it on his durango
http://www.summitracing.com/parts/PFS-80012/
Non-SFI approved, should I get the SFI approved one?

2. 1996 Water Pump: So I can run the water pump pulley

3. 34.5 belt???? Billy told me I can run the stock size belt.

4. New idler and tensioner pulleys.

 

i dont under stand why u need a new Harmonic dampener

Gates belt # k070951 (95.3/4in)is the belt im using on under drive pulling just 25% at the crank

u only lose a few inchs on the belt for new pully

 

Those pulleys fit fine on the stock dampner, dont know why billy would tell you that.
Ive swapped the pulleys back n forth a few times both na & running boost without issue.
Crank goes on tight but rubber mallet does the trick fine

Only reason I swapped dampners was for the 408 cause of it being internally balanced & 360 is external balance.(using sfi 5.2 dampner/5.2flywheel on 408)