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Apr 22, 2019 | 08:51 AM

CamoF-250

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Joined: Oct 2009

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From: Chesapeake

3G Swap

The overdrive pulley from my 2G alternator did not seem to fit the new 3G when I tried to swap them in order to maintain the same belt size. After looking online, I noticed most of the offerings for the 3Gs were 8-Groove pulleys. I believe my truck, and even the new 3G I sourced from a 3.8 mustang, has 6 groove pulleys. Did most 3Gs come with 8 and I just got lucky with a 6 groove model? I think my 2G pulley is just about 2” in diameter.

Apr 22, 2019 | 10:05 AM

More Turbo

Joined: Aug 2000

Posts: 721

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From: Floyd, Va

Some were 8, many were 6 groove. Mine was a larger frame 6 groove unit 130A from a Mercury Sable. With a sight amount of tweaking and re-drilling the hole I was up and running. Install took me about 2 hours with wiring.

Apr 22, 2019 | 10:10 AM

CamoF-250

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From: Chesapeake

I have mine installed my belt is just extremly tight now with the current 3G pulley, smog pump delete, and sagniaw swap complete. It might now be true but I had read that the saginaw swap and smog pump delete were one for one and would not change the overall belt size so the 3G pulley would be the culprit along with any difference as to the location of the center diameter. I did not need to grind the mounting tab at the top at all, just the back of the casting and it fell right in.

Apr 22, 2019 | 11:04 AM

Ddaybc

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Joined: Jul 2011

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From: Vernon, BC

I notice the truck in your sig is a 92. I don't know what came on the F150's in 92 but if it's like mine can you adjust your alternator? My 92 F250 alternator is an adjustable one so I can use various lengths of belts. My 3G alternator was built by a specialty shop and I asked them to install a standard size 6 groove pulley. The pulley on mine is 2 3/4 diameter.

Apr 22, 2019 | 02:24 PM

CamoF-250

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From: Chesapeake

The 92 5.8 has an ear at the top and at the bottom, adjustment in in the spring tensioner but I understand your train of thought.

Apr 22, 2019 | 04:11 PM

Ddaybc

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Joined: Jul 2011

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From: Vernon, BC

I see. Your 92 F150 has the same alternator setup as my 94 did. Non adjustable alternator and the belt kept tight by a tensioner.

FWIW, when I was researching the smog pump delete on my 92 I noted I could find belts in one inch increments, sometimes even in 1/2 inch increments. I know it could be a pain in the butt to find one but maybe an inch longer belt would work for you? I measured the length I needed with a string and then I looked mine up on the internet by going to the gates site and then cross referencing the part number to the brand that my local parts store carries.

Apr 22, 2019 | 10:21 PM

Skitter302

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Joined: Oct 2018

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From: Northern ID, Eastern WA

When I did my 2g to 3g swap I got a 3g from a 1995 Stang, Direct drop in didn't worry about the pulley. For a top bolt I went to the hardware store and started with a long one and trimmed it down to size.