Alternator conversion

Hi guys. I have recently rebuilt a 2.25 petrol engine which i got in amongst a job lot of bits totalling almost 2 land rovers neither of which i ever saw running. This engine replaced my 2.25 diesel. (some useless back ground for you)

I have converted to positive earth and fitted an alternator i found in amongst the ruck of parts, assuming it came of the petrol engine in the first place, as it seamed to have the correct cast mounting brkt However when i came to fit the belt it is too long, part number is 563132. Comparing the alternator to generator on my diesel the alternator pulley is about half the size, is this normal and if so does anyone know what the part number is or what series / engine i should refer to when ordering a new one?

Alternator is a Lucas 14TR


Thanks for any help you can offer. I have tried searching the forum but not found any reference to different belt lengths

I've cracked it. LR dont seem to do a belt for this alternator so went to my local motor factors and brought a 1m V belt which fits perfectly. Will let you know how this alternator performs once i get her back on the road