302 Crank Pulley not working on 350 LT1

[z28z11]

Compare my Pic #1 to the original shot of yours - I don't see that front ledge/projection that appears on mine - that's a good .250" difference right there, unless I'm looking at it wrong (maybe it's there, and just not visible - it sure doesn't look like it. You'll have to verify if it's present).

Regards -

[69Z28freak]

Hey Steve Here are some updated pictures. All of the pulleys currently on the car are stock 302 pulleys and the harmonic balancer on my '70 LT1 Motor is the same as the '69 302 motor. All of the Pulleys, Water pump, Power Steering Pump came off of a '69 Z/28. The crazy thing is that all of the pulleys lined up perfectly on the 302 motor. All I did was transfer the parts from the 302 to my 350. It would appear however that all of the pulleys are out by 1/4 inch from the crank pulley. This would lead me to believe that for some reason the 1182 350 crank is 1/4 longer than the 1178 302 crank.

Here the crank pulley is seated all of the way.



Here is the the crank pulley part number



Crank Pulley seated all the way



Water pump and power steering set up. Both of these units were on the 302 motor before mine and lined up perfectly.



This is a better shot showing the pulleys not lining up



And from the other side



Power steering pulley part number



Water pump part number

[z28z11]

Great pics -

I'm like you at this point - looks like the balancer is seated all the way back; I surmise that if this setup was the same on the 302 all the way around, it's got to be the crank, or the block seating surfaces for the water pump and pads for the power steering pump. What approximate production dates for the current 350 block and crank ? Later production ?

You will probably have to shim the water pump pulley, and the power steering pump at this point if the balancer has no more room to seat, or try another water pump and/or pulley combination IMO. Bummer.

Regards,
Steve

[69Z28freak]

Here is an update on the pulley situation. Looks like the crank pulley currently on my motor is 3-1/4 inches deep compared to the one on the original Z/28, which is 3 inches. That would explain the situation and solve the mystery, as was suspected. This should fix the problem. Now all I have to do is find a correct pulley and make sure it is the right depth.

Here is the one on my motor that may be a repop



Here is the original pulley on the 69 Z/28

[z28z11]

I'll try to get to mine and measure the depth. Glad you found the problem -

Regards,
Steve

[69Z28freak]

I'll try to get to mine and measure the depth. Glad you found the problem -

Regards,
Steve

Thanks Steve. I appreciate it. My guess is that if I go with all original pulleys I should be in good shape. I wonder if other repop pulleys are different dimensions than original as well. I have not heard of such a problem before, but I have seen first hand on many occasions, that some repop parts I have tried, do not work very well unfortunately. Gives a whole new meaning to the word "Close". In this case, close is not close enough, however.

[68Zproject]

I just measured the 69Z pulley I have and its 3 ".

[69Z28freak]

I just measured the 69Z pulley I have and its 3 ".

Thanks