I have found 3rd & 4th to be ok in fairness, however, 1st & 2nd seem too low (i'm in 3rd too soon), I was advised to change it earlier when the engine was in bits, but didn't heed the advice at the time..........did I dan?

I would prefer a final ratio of 4.7 due to riding style, which is generally in a small going group of 3 - 5 scoots (Avanti, Monza, tuned Rapido, Mallossi'd t5 and the like) who like to cruise at around the 60mph mark give or take. I very rarely tootle about town or go on evening rideouts, so it's with comfortable mile munching in mind.
Even with full riding gear on, i'm probably only around the 12 stone wet through variety, and always 1 up. Then there's the tent/bag, spare wheel etc', but as you can see, not too much weight.
Ok, with an eye on keeping the cost down, I now have at my disposal, an li150 italian box off a mate (ta Mick), and already have a 47t crown wheel & 17t front sprocket, so i've asked in the 'wanted' section for a stretched 81 chain (you don't have one do you Dan?). This will give me the desired 4.7 final drive ratio.
BTW.......ask a stupid question & all that, but i have 2 spare 80 link chains, and i notice AF do a link & a half for about £3, will that be the same as a stretched 81?
The bike's up at Ripon at the mo awaiting a bit of attention, so I thought the ideal opportunity.
Any advice greatly appreciated.