Spark plugs for Venturi

I was looking at what spark plugs to use in the Venturi 300 and stumbled across this post (see below) on a Peugeot forum.
My speedo has been playing up (showing +20%) for sometime and I wonder if this might be the cause. For the life of me I can't fathom out why spark plugs should affect a speedo reading, but..... Can anyone offer an explanation or suggest what plugs might be appropriate for my 300. MJG

"Make sure you use the proper Peugeot spark plugs in this engine (406 Coupe), unless you want problems later on.
See the parts man at your friendly ( HA! HA!) local Peugeot dealer.
Using non Peugeot plugs can mess up the engines running & make your speedo have a fit too!
And im not pulling your leg!"

These should be the ones Martin NGK BKUR7ET that is what is in mine now and runs fine. As for the speedo it may just need re calibrating which is common on these vdo clocks.

BH!! Six new plugs fitted in less than two hours and no skinned knuckles and.... found a solution to my speedo problem (see adjoining post).
Does life with a Venturi get any better than this?

HI MJG

What's this young man, going hands dirty yourself? Either you were very bored at home or the coffers are getting a bit light, whatever next? Still not time to worry about you just yet as no posts claiming golf is futile and you will never again pick up the sticks again!!!!!!

Just proving that Venturis aren't difficult to work on.
Just thought I'd get a little hands-on ready for the trip to Magny Cours' Classic Days. 80 Venturis booked in. I think its only yours that will be missing! Shame you are not able to make it.
MJG
Ps. One can't be golfing and holidaying all the time!

2 hours?!

Lol! Try changing them in the Bi turbo, 2 days more like.

Who refurbishes VDO speedos. The LCD display on mine is flickering.

I will dig out the number Richard and pm it too you bud.

Thanks Paul.

Hi Richard. Two days??? Sounds like an engine out job or was it a plug, pub, plug, pub, plug...jobbie!
M.
Ps. Might that be the reason they only made two of them!

That is my style Martin, the pub always helps with stress relief! Hope you get the right answers from vdo Richard.