1971 distributor & engine specifications for the 400
 

This was the GOOD year for the 400 engine before it was smogged to death.

Distributor part #D00F-U
Centrifugal Advance Start: 0-0.5° @ 350RPM Finish: 14° @ 2275RPM
Vacuum Advance Start: 0-1° @ 5" Finish: 12.5° @ 25"
Point Dwell: 26-31°
Initial Timing: 10° BTDC, 6°BTDC California.
Vacuum given in inches of Mercury (Hg).
RPM specified as distributor RPM.
Degrees specified as distributor degrees.

Double those values for crankshaft figures:
example 0-0.5° @ 350RPM distributor becomes 0-1° @ 700RPM on the engine.

Engine specs for the 1971 400:
260HP @ 4400 RPM, 400 LB-FT @ 2200 RPM (Brake/flywheel figures)
Compression: 9.0:1
Carb: 2V
Engine code: S
Available in: Custom & C-500, LTD, Galaxie 500, Monterey

Does the D00F-U distibutor use points or is it designed for the stock electronic ignition used on later models?

My parts supplier is having trouble finding the vacuum advance for it but found a listing for D00F-V. I picked up the vacuum advance for that one but the linkage does not align properly with the internals of my stock distibutor. It is going back tommorow.

I have a 1978 F-150 with a mildly built 400 and C6. I recently moved from 3600 ft down to near sea level and am having a little pinging issue.

The DOOF-U unit was a points distributor. I think I had to modify the linkage on the last vacuum unit I messed with. When you get into custom stuff sometimes a little fabrication is required to get it done right.

I listed the part number for the vacuum unit at Oreilly? somewhere here in another post.