BF 32 Autolite

[68blk500c]

Another option if you want to use BF32's is the Autolite #34 plug. After Ford and Autolite separated in 1972, all Autolite plugs got the Motorcraft name, Autolite continued making plugs with a new numbering system. The BF32 was now Motorcraft while the Autolite version was #34, same exact plug. You can find Autolite 34's cheaper than BF32's, here's a set on ebay now:

https://www.ebay.com/itm/127812391980

Does the same hold true for the BF42 plugs??  Did they become 44??

[s2ms]

Does the same hold true for the BF42 plugs??  Did they become 44??

The BF42 became the new Autolite #35. After a while the Autolite 34 and 35 were both phased out and replaced by the Autolite #45. Never used the 45's myself but have heard they work well in a 289 HiPo, same heat range 5 as BF42 and 35, the 45's are still available.

I think the Autolite 44 might have been a successor to the 34 (same colder heat range) but it seems to be obsolete now.

[NC TRACKRAT]

A few years back, I tried a set of the AUTOLITE 45's and found that they run on the cold side and have a tendency to foul.  It all depends on your engine and how it's tuned. If yours is higher compression and/or has been bored out and tends to run hotter, they might work. Otherwise, pony up and get the BF32's.