Shall we run a book on how many posts there are before the thread gets closed?
Sorry Rob, but just wait....
In keeping with my recent behaviour, I'll be naughty and kick it off.
Actually, not really. But...
Rob - "Samuri conversion" is a term that grates on people. Spike didn't invent the idea of sticking on triple carbs and doing a bunch of internal work on a Z engine, so try not to use the term!
As Johny notes, its a series of complementary changes. Adding triple Webers, Dellortos, or similar doesn't really work in isolation. Unless you are just trying to overfuel your engine and waste money. A triple carb conversion (which is, on the surface, an easy peasy bolt-on) needs to be matched with supporting head porting to optimize performance in that component. Also, a larger than standard lift/duration camshaft is needed. Finally, you would preferably optimise the exhaust side too, moving to a tubular manifold of a suitable size and design. You will then need the car rolling road tuned to get the jetting right based on the performance and characteristics you are after.
Doing it properly is thus rather expensive. You will gain power - exactly how much will be affected by assorted variables as above. Its not hard to get 200hp. You are still going to want basic driveability though, considering the use of your car, so would probably be happier with less horsepower and smoother performance.
Just seen Rob G's post as I typed this - that might be a better suggestion. The L26 is basically a L24 (P30) block with an L28 crank and rods in it. If you get it bored from the standard 83mm to 86mm, pop L28 pistons in, you basically get an L28. Change the manifold and exhaust to something like Sean D sells.
Either way, neither approach is a bolt-on upgrade. Engine apart or out will be necessary.