Reviving the thread to ask about the belt tension. I've got two of the early engines to do, Haynes says set so that the belt can just be twisted through 90 deg, then you must get it set accurately with a Fiat dealer. Elsewhere I've seen an audio device used and assume that's what Fiat use.
As you can imagine, I've no intention of going near a dealer - so has anyone come with a genius idea to get around it?
(On boats we use a tension gauge which hooks around a shroud, and as you pull one part of it it distorts the wire and a needle tells you how much tension's in it. A car version would be really simple too).