May 21, 2012

LSx (LM7) Low Mount Alternator DIY

Parts needed. Note this will delete your power steering pump and a/c and add more HP. Plus it will remove that nasty looking truck alternator bracket.

  1. Fbody Alternator Part #12563327. $20+shipping.
  2. Ribbed Pulley - Gates Part #38008 = $20 O Reilly
  3. Gates Belt – K060547 – $20 O Reilly
  4. 2 Long Bolts for alternator bracket (M10 x 1.5 140MM long). I ordered mine from Grainger for $10 and received 5 of them.
  5. 1 Shorter M10x1.5 about 50mm for ribbed pulley
  6. A 1/4 – 3/8 washer. You might have to drill out the center. Depending on what you get. This acts as a spacer on the back side of the ribbed pulley.
  7. 10mm x 1.5 Tap
  8. 11/32 drill bit
  9. 3/4 in spacer to space the alternator off the block to line up with the water pump and crank pulley. You will also need some type of straight edge to make sure you get it right.

Look at this HIDEOUS truck mount for the alternator. Talk about the MILE high club.


Tap your block here. I screwed in the lower bolt to the fbody alternator bracket and used a pencil to mark dead center on where the new hole needs to be threaded.

photo 2

Then I drilled the hole a little over an inch deep with a 11/32 drill bit.

photo 4

Now we need to tap it. Use some tapping oil or watch a YouTube video if your not sure how to do this. Make sure you drill it straight and tap it straight otherwise your screwed and you really only have one shot at this.

photo 5

Tapping the threads is the scary part. Error on using lots of oil and pulling out (lolz) and cleaning it after each turn.

I ended up cutting my 3/4 in spacers using the ones on the original truck bracket. One was exactly 3/4 the other I had to grind down a bit.

photo 1

Use your 1/4 – 3/8 spacer on the back side of your ribbed pulley. This should be enough to line it up with your crank pulley. Check with flat edge. Make sure to go from the first rib on the pulley and not the front. When lining it up.

Here is the end result.

photo 8

It looks 1000X better.

photo 7

I hope this helps you out. Any feedback is appreciated.


  1. Hello Mr.Andrew
    i have a problem with your app of Android Bluetooth at this
    it's important for me i wish you reply !

  2. I love you man, this is perfect!

  3. Great info !! I order all the parts !! Thank you ....

  4. No problem man! Glad it worked out for you, comment here if you need any more help. --Andrew

  5. OK I'm an idiot. did you cut the new bracket from the old truck one or is something else.

    1. No worries, you will need to use the "Fbody Alternator Part #12563327. $20+shipping" for spacers you can make your own I cut apart the old alternator bracket for my spacers.

  6. This comment has been removed by the author.

  7. If using fbody pump and balancer do you need the spacer?

    1. Umm I don't think you will, but you will prolly need an fbody tensioner.

  8. Is there room for a motor plate behind the alternator?

  9. If you go this route with an fbody alt bracket, like you did, do you use an lm7 truck water pump? Or is the major difference from a truck and fbody water bump the routing of the hoses?

    1. For this setup I ran the lm7 truck water pump.

  10. Awsome writeup. Will this work with forward and down factory manifolds for a turbo setup?

  11. This comment has been removed by the author.

  12. an electric start, count the seconds: "One thousand one, one thousand two, one thousand three, one thousand four" and so on, with the key or start button engaged aftermarket water pump kits has lots of resources for the boating trade and public alike

  13. I high value this post. It's elusive the great from the terrible now and then, however I think you've nailed it! would you brain overhauling your web journal with more data? Mercury outboard boat parts

    1. Will this work for the 6.0L LQ4 engine also?