most cases it will make more torque with injectors further upstream due to longer time to homogenise. usually at the expense of throttle response/idle quality. depends how its set up tbh (batch, sequential, paired)
Also, due to the fact that the intake runners 'funnel down' from 1 5/8" to 1 1/4" this will cause an increase in air speed.
The other thing to bare in mind is that these injectors are actually closer to the head than the main jet in the original carburettor set up. They look long, but the new runners are actually the exact same length as the stock inlet manifold runners
I said previously, that I wasn't happy with the link I made for the two banks of throttle bodies, and could see it failing. So, a new plan was hatched. This was to make something along the lines of your standard twin Webber linkage.
A couple of Aluminium brackets were fashioned from some angle, and these then welded to a piece of Aluminium tube;
I also made a couple of brass bushes for the ends.
However, it soon became apparent that my original idea of making some levers to attach to the throttle spindles and using connecting rods wasn't going to work, as due to the compact design of the bodies and links, there simply isn't enough room to get a lever in and keep enough travel to open the butterflies fully. Bumhats!
Plan 'B'. Back to cables. Two brass 'nipples' were made and soldered onto the ends of two short lengths of stainless Bowden cable.
These could then locate in the original throttle actuators
Now, I needed to anchor the other end of the cables to the levers I'd made on the throttle shaft, BUT, I needed to have some way of adjusting them to balance the two banks of ITB's to ensure sycronised operation.
So, two short pieces of M5 bar were made, drilled and soldered onto the end of the cables. This then screws into the M5 rod ends I'd got already to use in plan 'A'
A length of 1/4" bright round bar was cut and a couple of lever arms made. These were then welded exactly in alignment with each other.