Single Groove 340 crankshaft pulley

[mopar1]

I have a cast crank 340 in my 'Cuda and need to know what the correct single groove crankshaft pulley would be for it?  My current pulley requires a spacer between it and the balancer, a washer that is about 3/16" or so thick and I don't like having this on the car. The crank pulley only drives the water pump and alternator pulleys. My car has the mopar performance aluminum water pump on it if that makes a difference.  I have perfect pulley alignment between it and the alternator.  The crankshaft pully just doesn't protrude out far enough.

[71vert340]

 My two questions are: 1.) What is the diameter of the belt groove you are currently running and want so as not to overdrive or underdrive the engine accessories and 2.) what is the height of the pulley from 6 bolt flange face to the belt groove or large diameter face? I know some members have stacks of pulleys available. We just need some measurements. I can measure my stock 340 but it has a forged crank. I have 360 pulley I can measure.
Terry W.

[71vert340]

 A quick measurement of the stock 71 pulley is about 6.5 " across the pulley face and my belt sits flush with the top of the pulley groove. The measurement from the harmonic balancer face to the middle of the belt groove is about 2.125". The 360 pulley 3 groove I have is much larger ( over 7")diameter. Someone may have a later 340 single groove pulley to compare my measurements to from my 340.
Terry W.

[mopar1]

My two questions are: 1.) What is the diameter of the belt groove you are currently running and want so as not to overdrive or underdrive the engine accessories and 2.) what is the height of the pulley from 6 bolt flange face to the belt groove or large diameter face? I know some members have stacks of pulleys available. We just need some measurements. I can measure my stock 340 but it has a forged crank. I have 360 pulley I can measure.
Terry W.

Hello Terry,

Thank you very much for your feedback.  I'll try to take the pulley off this evening to get measurements and I'll post them once I have them.

[mopar1]

The overall height of my crankshaft pully is 2.25".  Image attached.  The width of the v-groove is 11/16.  Divide that by 2 and subtract from the overall height, is 1.90" which is the distance from the face that contacts the balancer to the center of the v-groove.  The diameter of the pulley is 6.5".

For additional information, the water pump pulley height from the face that contacts the water pump to the outer edge is 2.5".  It's v-groove width is 5/8".  Divide that by 2 and subtract from 2.5 and it's 2.1875.  the overall height of the water pump pulley is 2.6875" and it's diameter is 6.5" as well.

The makeshift washer spacer (image attached) I made to go between the crankshaft pulley and the balancer measures .295" thick and it's still not enough for a perfect alignment of the water pump and crankshaft pulleys.  It could go at least another 1/8" to 3/16" just eyeballing it.

[mopar1]

I found this image on Bouchillon performance's website and checked my engine's measurements and they are spot on with the 4 17/32.   After looking closer at the water pump pulley, I have a big block water pump pulley. 

If anyone has a small block water pump pulley let me know!