2.25 carbs - fuel off solenoid? LPG conversion.

Chaps,

I'm picking up my new (!) 1977 S3 109 Landy on Friday, so I don't yet know which carburettor it has on it.
I'm looking at converting it to LPG+ petrol dual fuel using a BLOS volumetric mixer sitting just before the carb.

Two questions:-
1: Which carbs that fit the landy have a fuel cut-off solenoid?
and
2: does the solenoid cut off the fuel before or after the float chamber, as this has an impact on the changeover control philosophy.

Also 3: The current owner doesn't know if the head's converted to lead-free as he's only had it a few months. What do you think the odds are?

I think most only cut off the idle circuit rather than the main jets so are not suitable for this job (I know the DMTL does). i.e. it will still run with the throttle open just not idle.

There's mixed opinions on lead free, I got mine done when I had the head ported but I've hear of other people running unleaded on old seats for years with no problems...the higher heats of LPG may cause issues though.

If you're going LPG it might be worth getting the head skimmed anyway as a higher compression ratio can be a good thing with LPG so long as you don't go mad. ACR or Turner both do ported, skimmed heads. Standard landy heads are pretty meaty and have a lot of spare metal that can be taken away.

Did you know that you don't have to start you engine on petrol when you have lpg installed? I ran my v8 for years without a petrol tank fitted and it start very easy on gas hot and cold. The lpg kit I fitted to my landy had a valve that was put in the petrol pipe and was electrically controlled from the gas switch in the cab. The valve should go between the pump and the carb.

Thanks for the input chaps - most useful. Unfortunately the deal fell through on the landy so this is moot at the present, but I'll be back when I get one sorted out....