How To: Holley Crank Trigger

Holley PART# 556-115 is a good way to get accurate timing on your small block Ford. It uses a 35 tooth (36-1) trigger wheel and a hall effect sensor.
If you follow Holley’s instructions you will end up with several issues:

  • The crank trigger will hit your water pump
  • The pulleys will be moved outward requiring all accessories to be moved out as well.
  • The pulleys will not rest on the spacer hub, with the potential for it to wobble.

With some machining all three can be avoided.


Start by removing 1/4″ off the face of the spacer, but LEAVE THE HUB. The photo is hard to see.


The crank wheel also needs to be machined. There is a lip on the outside which will keep the wheel from sliding all the way on to the spacer. After the lip is removed it will fit flush against the spacer as shown.


The water pump needs to have some material removed so the wheel won’t hit it. I removed much more than this on an old pump and there was no problem hitting a water passage. It would clear fine with less material removed than shown here.


Also the two spacers that hold the sensor need to be shortened so that the sensor lines up with the edge of the wheel.


Final images show the results.

Crank Trigger Progress and Painted Plenum

Despite the heat I’ve made some progress on Mr Orange. I had to get the Holley crank trigger wheel and my pulley spacer machined. Waiting on getting them back from the machine shop. Here is the bracket that holds the hall effect sensor.


I also painted the plenum.

Motor/Trans are Out

After a bit of sweaty work last night I got the motor and transmission back out. Tonight I will separate them and then get the the transmission to the re-builder and get the engine on a stand so I can swap in the 303e cam.

I’m also going to need a new bag of cat litter…