Engine suffix

I phone up our local Landrovers dealer and was going to order a new distributor cap and leads and I told them the year and it was a series 3 petrol
Swb and all that and they rang me back a bit later and asked me what engine suffix it was ,please tell me how to find this information ive looked at Haynes manual , plate by rad in me Landy I don't know where else to look

lhs of engine front top edge of block just behind water pump

May not be relevant as you might not have the original dizzy - and `i'm not sure you can identify the dizzy from the engine number prefix. Dealers always seem to want this sort of info so they can look things up in books. You'll either have a ducelier or a lucas dizzy fitted - there's already a thread on here about identifying which is which. If your dealer can't sell you a cap from the name, or even a description of the dizzy, go to somewhere that actually knows about old landys. Most of the mail order places are good.