I have a 440 that I have been trying to figure out. It has a rough idle. I believe it has a vacuum leak. The cam is a older Hughes brand that has around 228 degrees duration at .05 lift. So I think idle should be OK. The engine is rebuilt with all new components. I had the heads milled and the intake milled to match. When timing the engine the timing marks do not line up were they should. The timing marks are off by arround 30-40 degrees. The damper may have shifted but I don’t know for sure. The vacuum at idle is about 7 inches.

My questions are

Would the engine idle OK if the timing chain was off by one tooth?
What affect would that have on were the engine liked to be timed?

I plan on putting on a new intake manifold gasket set and getting a new dampener but I would like to rule out the camshaft being out sync before I start.

I drive the car and it seems to run fine once off idle.

Thanks
Sanman

Sounds silly but make sure your spark plug wires are on correctly. I hear that a lot of people mistakenly cross the #5 and 7 wires.

I will check the spark plugs 5 and 7. I have a thing to put in the spark plug hole to find TDC. Ir did not line up with the TDC on the damper, so I'm ordering a new one now. Once I get the new damper I could check the cam phase by taking off the valve cover. Then I will try to tackle the vacuum leak.

Thanks