Came with a 292 that was supposed to be out of a 1955 bird.  Had a 56 block and 57 heads.  Is this a 57 distributor?

Thanks
Paul

Paul sent to me one of the new TSP distributors designed specifically for the ’55-’57 Thunderbirds.  The packaging on the supplied box says TSP and not CRT.  This distributor is mechanical tach capable.  The quality of the parts looks good and some careful measurements of the gear placement on the shaft found it to be 4.983” collapsed and 4.998” extended.  The specification within the 1957 Ford service manual calls for the collapsed measurement or pushed up dimension to be 4.991-4.996” with end play being 0.022-0.030”.  My experience has shown that the distributor hole measurement should fall anywhere between the extended and collapsed distributor gear measurements.  I measured the distributor hole depth in the 312 dyno mule and it is 4.990”.  That makes the new TSP distributor correct in its gear measurement as the gear will not be in a bind when installed in the block.
 
As a FYI, the MSD distributors do have their distributor gears placed higher on the shafts (reduced collapsed measurement) than what’s called for in the Ford manuals but after having dealt with a number of blocks that are machined on the shallow side (not deep enough), I can understand the reasoning for having the gears higher rather than lower on the shafts.  Having the gears not running on the distributor pad in the block is not an issue for the MSD distributors.  No major issues with the gear being on the high side but any gears that are too low can have some severe wear issues in that area.
  
The distributor cap on the TSP distributor is ~3/4” higher than the MSD cap so switching the wires from the MSD cap to the CRT cap was not an issue.  Both caps in this case incorporated HEI terminals so no problems were encountered in switching the spark plug wires from one cap to the other.  With the ignition timing for the CRT distributor set exactly the same as the MSD distributor (39° total), the engine was run on the dyno and it made exactly the same horsepower as the MSD distributor so the electronics are doing their job.
 
I found no issues with this new distributor so I heartily recommend it to anyone with an early ‘Bird wanting to retain the factory mechanical tachometer.  Be forewarned that there are blocks out there with distributor cavities that are on the shallow side and appropriate changes must be made to accommodate those particular blocks.  That would involve either relocating the gear higher on the shaft for those shallow holes or a thin shim where the distributor and the block mate up to space the distributor up accordingly.
 
This particular distributor gets a clean bill of health and will be prepared for use in Paul’s engine.

Lorena, Texas (South of Waco)

Good information, thanks.....................

64F100 57FAIRLANE500

Good morning, Ted.

I'm confused by your numbers. There's approximately a 1-inch difference in gear placement between the CRT and the 57 manual specs. Is this a typo?

Thanks

Good catch as that was a typo.  I’ve gone back into that post and fixed that.  Only the inch number changed and not the decimal portion.  Thanks for the alert to that.

Lorena, Texas (South of Waco)

Based on their description, I think the CRT and TSP are the same distributor but sold by different vendors. Neither has an adjustable vacuum advance. Is that an issue? CRT's site said that 8mm Packard plug wires also are available. Has anyone purchased them with the distributor? If so, are they a direct fit?