Currently rebuilding a 1600TP and I was wondering if it's worth upgrading to a 1776 , adding the cost of new barrels/pistons and the machining required to the case and cylinder heads is it a worthwhile operation ?

Have you driven a buggy with a 1600 tp? Most think it's perfectly adequate for a car so light with quirky handling.

If you're going so far as to build a 1776 you may as well factor in a decent cam c/w followers, steel pushrods, bolt together valve gear, 3 angle valve job, h/d valve springs, 8 dowel crank and dynamic balancing etc

It depends on the depth of your pockets and (these days esp) parts availability.

Personally,
I would either keep the 1600 and stick a big set of carbs on it as 1776, whilst a worthwhile upgrade, is just getting to be eyewateringly expensive to do - If you want more grunt and more cubes, then why not stick a 2 litre Type 4 or T25 in there - far easier and cheaper option for more power.

Never looked back since I did it on mine

A 1600 or 1641 (whichever is cheaper) engine with twin 40 Kadron Solex (or whatever they're called now that Empi make them) or twin 34ict Webers and a decent 4 into 1 exhaust can be a great buggy engine.

I'm going to be against everyone else just as I can! If the case is good and all the parts are good why not" If U are buying new P/b anyway there is about £100 in them and £200? for machine work.. And you will end up with a low rpm 1776cc By doing it you have made back the £300 just in resell.. If you did end up selling it as 1776cc are all ways wanted.. And bits can be added like a nice Cam. Head's.etc  And to top it off you can say you got a 1776cc ..

I'm going to be against everyone else just as I can! If the case is good and all the parts are good why not" If U are buying new P/b anyway there is about £100 in them and £200? for machine work.. And you will end up with a low rpm 1776cc By doing it you have made back the £300 just in resell.. If you did end up selling it as 1776cc are all ways wanted.. And bits can be added like a nice Cam. Head's.etc  And to top it off you can say you got a 1776cc ..

The most fun buggy that I ever had was a swb GP on 7" banded steel wheels, E70VR15 Jag remoulds and a standard apart from dual cannons, 1200 motor. Such a lovely little thrashable engine! Loads of fun and would still have been perfect for today's roads of speed bumps, 20mph limits and speed camera vans...

The most fun buggy that I ever had was a swb GP on 7" banded steel wheels, E70VR15 Jag remoulds and a standard apart from dual cannons, 1200 motor. Such a lovely little thrashable engine! Loads of fun and would still have been perfect for today's roads of speed bumps, 20mph limits and speed camera vans...

I think that you need to get out more 

I'm going to be against everyone else just as I can! If the case is good and all the parts are good why not" If U are buying new P/b anyway there is about £100 in them and £200? for machine work.. And you will end up with a low rpm 1776cc By doing it you have made back the £300 just in resell.. If you did end up selling it as 1776cc are all ways wanted.. And bits can be added like a nice Cam. Head's.etc  And to top it off you can say you got a 1776cc ..

If you are going to machine for a 1776 , you might as well go for a 1914