Is there enough room at the front for a float chamber to fit? The wing is quite close.
The problem with having the float chamber that close to the exhaust manifild is heat soak. Although your set up may not have had a heat shield originally, I would definitely fit one now, especially with that arrangement.
This one on the link appears to show your set up.
"TR3 TR4 AUC878 SU H6"
A quick surf on Google pictures shows that TR3's did have carbs like this, but the ones I saw had both float chambers on the other side.......
