Brake fitting

I have a brake master cylinder with servo, single line from a lwb and was hoping to fit it to my swb 2a. Now the brake fitting is different. My question is what size do i need? Dont worry I will be testing it rigorously off road before venturing on road.
Billy

You will probably need to post some pictures of what you have to get some meaningful advice

If its old it could be 3/8 or 7/16 UNF but if its modern it could be metric. What does it measure up as?

I think LWB and SWB have different masters.

Yes, there are differences between SLS and TLS brakes, dual and single circuit and the dual and single are connected differently between the SWB and LWB, and the dual masters can have two different threads sizes, but I hope the OP has take all this is into account since they are modifying their brakes. The question was about the fitting thread. Personally I would not make the proposed modification, I would install dual circuit brakes.

Yes, its a can of worms. I have old spares so am going to convert to the swb tls set up. I have done everything I can to get the original set up to work well. Thanks for the advice.

If you don't mind a bit of work then a really good set up is the TLS fronts, S3 servo pedal box with the dual circuit and the 9" (if I recall) servo from an early 90. You have to make an adaptor plate and packer for the servo and get an aftermarket servo with a threaded on clevis so you can take it off and swap it with one that fits the S3 pedal box. Once its done you have really good brakes. My LWB stops pretty much like a modern car. The early 90 servo is the same as the Santana one Haystee sell but without the cut out to clear the steering column (and about 1/3 the price..), but once you have fitted the 3/8 packer / adaptor plate it clears OK.

Thank you for that, my last series three had the 10 inch sls dual circuit with servo, and stopped ok. I am hoping to get really good brakes so I will set up with the spares I have and the tls and dual circuit and see how she stops.
Many thanks for the insight.