Installed new 347 stroker but belt keeps walking off

[Gintstone]

Hi guys got a problem with my new motor. Bought a used 347 dss stroker from one of my buddies, put the motor in and got everything together and am having problems with the SERP and procharger belt walking off the pulleys. I took off the fan and shroud and noticed that the crank pulley off about an 1/8” Compared to the rest of them. This new motor came with a balancer on it, my old motor had a romac balancer on it. I’m unsure what to do. Can I shave 1/8” off the crank/procharger pulley? The romac balancer is a different balance weight than the balancer on the 347, so I don’t think I can just swap the balancer. Any ideas are appreciated, thx guys. I tried uploading pics but apparently they are too big

 

[JimmyJames’s84]

I don’t have a procharge but my 347 does the same thing on the Alternator. Did you figure it out.

 

[347HO]

In my experience, belts which "roll off" is due to one or more pulleys not in same "plane" or "parallel" or both.

Quickest way to check this; place a long straight edge on the drive pulley and pass it in front of the accessory pulley. It should be parallel and on plane.

Good luck

 

[JimmyJames’s84]

I have done that and they are all the same. We made a bracket to strengthen the alternator bracket thinking that is was banding. But that did not work. Maybe I need to get new pulleys and brackets. What pully set up do you have.

 

[347HO]

I use a gilmer setup.
Alignment as I mentioned above keeps my belts from rolling off.