Yes, I said that was what my 1966 manual called for. I also mentioned they crossed over to the NGK. Personnaly I run the NGK.

Did someone say Champion plugs? I wouldn't run those in my lawnmower! I cross referenced what it took and put in NGK. NGK or Denso all the way. I used to run Bosch in everything, but haven't had any luck with those either.

My first post was refering to recommendation from the MPI workshop manual.

Alex, if you could ever find a set of B6ECS with the 'oblique electrode', t'would be great. 

I don't know if they ever made them in '6', but B7ECS is available.  I've heard rumors amongst the orsche / VW crowd that the '6' was/is available.  I know that I'd like a few sets.

Are you sure about not needing the R plugs? I don't know specifically about the SPi but the R means that it is a resistor plug which is usually essential for ECU controlled engines. Non-resistor plugs generate a huge amount of EMI which wreaks havoc with many ECUs. Sometimes, you can get by without them if the wires or the caps are resistor type.

BP6ES will do just as well, you don't really need the R bit.
Non-projected nose B6ES plugs work better than the more common BP6ES projected nose in a carbed car, not sure about an SPi.

I do have some OEM Unipart plugs kicking about somewhere at Dr Paul's.

My owners manual for 76 mini 1098 calls for Champion N-9Y, .025 gap.  Cross references to NGK BP6RE.  Not sure about MPI/SPI.

this plug doesn't wear out...iridium plugs,  the best there is, designed for the mini.

yes.. the ONLY one to use for ANY mini..  part # 7333 at advance auto parts..

Not sure if the SPI is the same as the MPI, but the MPI workshop manual says 0.80 - 0.90mm, NGK BP6RE. 

Are the NGKBP6RES the best plugs for a 1275 SPI? If so, what's the recommended plug gap?