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Discussion Starter #1
I have a Frankenstein 400 4bbl where the block is from a 69, the heads are 73 and various other parts in differing years. What should the timing be set to? Looking at the specs from 69 thru 73, some years calls for different timing amounts (for example, 69 shows 9 degrees, 71 jumps to 12 and then in 73 it is up to 13). Appreciate any guidance. Thanks
 

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Discussion Starter #2
BTW - I did read the sticky and it says to start with 16. Just wondering about the different specs called for by the various years, and which component of the motor (block, heads, etc) would dictate which to use. I'm guessing it would be the block, but looking for others thoughts. Thanks
 

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64-67 Expert
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8,561 Posts
Blocks are all the same, as are the pistons, originally. Pontiac changed compression ratios with heads. Spec for my '65 and '67 GTO's is 6 degrees BTDC initial. Later GTO's, about 9 degrees. I'd start out at about 8 to 10 and see if it'll run without detonation. 16 degrees initial is too far advanced and will give your starter a workout.
 
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