msd crank trigger

[1970chevy]

i just bought a sonnys 555bbc i got here and it need the crank trigger so i went and bought a msd part # 8620 crank trigger and its for a 8inch balancer i got it home and i have a 7inch ati balancer on does that matter or should i pick up a sbc 7 inch crank trigger i am new to this crank trigger
thanks

[pumpgas]

Originally Posted by 1970chevy

i just bought a sonnys 555bbc i got here and it need the crank trigger so i went and bought a msd part # 8620 crank trigger and its for a 8inch balancer i got it home and i have a 7inch ati balancer on does that matter or should i pick up a sbc 7 inch crank trigger i am new to this crank trigger
thanks

You will def need the big block mounting brackets I would just run the 8620 and call it a day won't hurt a thing the ignition has no clue how big the balancer is.

[1970chevy]

thank you i never delt with a crank trigger are they easy to run for a ignition box i am using the new msd 6al-2 box it looks easy to wire in thanks for your help

[nxtruck]

In my opinion, they're easy to set up, once you understand how everything works. You no longer set the timing by turning the dist. You adjust the timing by sliding the pickup sensor up or down the engine bracket. Turning the dist. adjusts your rotor phase. When you are ready to start the engine, you'll want to turn the engine until your timing pointer is pointing at your desired timing mark on the balancer. Then, you'll need to make sure that your trigger wheel is clocked so that one of the 4 magnets embedded in it is timed with the crank sensor. Once this is done, make sure that your rotor tip is pointing at the #1 terminal in the cap (rotor phase). Now, if everything else is in order, it should fire right up.
One more thing. If you're using a regular distributor with the crank trigger, you'll have to lock the advance mechanism out, as not doing so will allow constantly changing rotor phase.
Your 6AL box should have a violet/green 2-wire harness with it. This would normally plug into the magnetic pickup in the dist. With a crank trigger, it will plug into the crank sensor. Make sure that you route this harness well away from any other wiring, as this can cause all kinds of EMI-related problems if the harness is too close to other wires.
Sounds like you have a nice engine there. Good luck with it!!

[1970chevy]

thanks