quote:
Originally posted by jb1490:
... 10° is from a late '71 with a build date of 10/71. From what I have observed, the 6° was changed to 10° late in the '71 "production" year ...
... increased from 29°-24° to 34°, which indicates that the distributor was changed to dual points instead of the (earlier) single points distributor ...
John & all. You may find this interesting. As I remember it, the M-code engines were all specified to have 6° distributor advance. As was the 1971 Q-code engine (Cobra Jet). The 1972 - 1973 Q-code engines were all specified to have 16° distributor advance, except for those installed in Cougars (they were 6°). And the 1974 Q-code was specified to have 20° distributor advance. It was the R-code engines, the 1971 Boss 351 and the 1972 351 HO, which were specified to have 10° distributor advance. I've been told by a few owners over the years that their Pantera had been factory equipped with an R-code engine. This seems to corroborate those claims. John, any chance that late 1971 Pantera has (or had) a solid tappet engine in it?
All of the Q-code engines installed in Panteras (and R-code too) should have dual point distributors. Out in the Mustang/Torino world its a little more hit and miss, but in general the Q-code engines mated to manual transmission had dual point distributors, those mated to automatics had single point distributors, but this was a little more unpredictable (and seldom reflected in tune-up manuals either).
I know this goes against the grain of some folks, but the M-code versions of the 351C 4V were low-buck entry level performance motors. They had the same crankshaft damper as the 2V engine, single point distributors like the 2V engine, they really weren't specified to rev beyond about 5000 rpm. The Q-code versions had a heavier crankshaft damper, dual point distributors, bigger carburetor. They were top-of-the-line performance motors in their era, and were meant to rev to about 6000 rpm.