One commonly published figure for Pontiac 400 of our vintage says pistons down .023 in the hole. I have a bone stock original unrebuilt '67 400 with pistons down .018 in the hole.
What has changed in the past 40 years that a factory built 400 can no longer run well, given all in mechanically good condition with reasonably low mileage (just over 77,000)?
Fuel.
And if I am not rebuilding my '69 400 (no reason to other than because it has never been) then why should I have to zero deck it to make it run well? The only change from stock is the timing set. It ran the same before it, but the ignition timing had more variation with the worn gears and chain.
And why do some engines have more issues than others, even those that were built using the same parts?
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
