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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: rockable on November 05, 2012, 07:03:05 am
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I will check this with a top of stroke indicator before I install it but I'm out of town right now and wondering this. My 305 had the timing indicator at the 12:00 position. You had to shine the timing light down behind the water pump.
The new crate engine comes with two sets of indicators but they mount in the more traditional 2:00 position. I changed over to a new harmonic balancer, which has the mark machined into it. Something has to change in order for this new position to be correct. Do they machine the key way in the crank in a different position? Inquiring minds want to know.
Also, I got 4 dowel pins, 2 a little larger dia. and 2 a little smaller. The large ones go in the crank/flex plate position and plug the alternative dipstick position. Where do the two smaller diameter ones go?
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I'm currently dealing with the same problem. You need the proper balancer with a 2 o'clock timing mark, thats the easiest fix.
Or if you can precisely measure and re-locate the line yourself, it can also be done. Read this. http://www.crankshaftcoalition.com/wiki/Timing_tabs_and_damper_TDC_lines_SBC
Easier to move the line than machine a new key slot, lol
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305's have the 12 O'clock position on the balancer and 350's have it at the 2 O'clock position on the balancer.
I went through this situation a little while ago. Previous owner dropped in a Goodwrench 350, but used the 305 balancer on it. The motor will run fine but its almost impossible to time it correctly. The carte engine has the timing pointer (on the timing cover) at the 2 O'clock position, and my 305 balancer was marked at the 12. I replaced my balancer with a 350 style and all was well with my timing light.
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Using a Tdc indicator, I marked the correct location for my new timing indicators, pulled the balancer off and cut a new groove with my bandsaw. Piece of cake. If I had known about this, I would have specified a 350 balancer. Take note.
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This is absolutely wild...I literally just went through this same deal on saturday with my gm goodwrench....i even ordered a new 6.75" balancer and obviously ordered the wrong one! i used a dial indicator and found the top of the stroke and split the difference between the stationary point and ended up scribing a new line! Wild that i just read this.
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I'd love to know why they were different. Makes no sense to me.