Seeing as I do love spending hours searching for things on the internet I would just like to see if someone can confirm and answer a few carb questions.

I read somewhere that XJR400 carbs are the same fitment as GSXR400? Is this true? If so is it model specific?

What what I have read the engines on all GSXR's and Bandits are similar. Would FCR carbs for one model gsxr/bandit fit a different model?

Are there any other model that share the same fitting carbs?

Does fitting FCR carbs mess up SP's due to the tps?

The GSXR and Bandit sharing the same engine is wrong, they share parts of engines, especially the gk73a and B4 but loads of parts are single fitment. The 76a has even more differences and not that much fits.
I imported Mikuni TMR carbs for my GSXR 73a that were for a GSX400X thinking the engine was from a B4 and parts of it may be but they would'nt fit and were loads wider so i had a hole in the head gob of reracking them.
The info regarding XJR4 FCR's is related to the 73a and were used buy Jay from the usa on his 73a race bike.
Ive no 76a carbs to compare so cannot say if the XJR carbs fit the 76A, same with B4 FCR's.
If you measure the distance between each carb center line you can get spacings for FCR carbs.
The 73a/B4 spacing is 66-81-66 same as XJR and Bandit FCR's.