The rear pull-off models work fine, but the pull-off sticks back pretty far and on some set-ups can interfere with other items on the intake.
We stock all the parts for those, including the pull-offs which are starting to become a bit difficult to obtain as they are cutting part numbers out of the catalogs all the time.
We always replace the factory E-chokes, they usually fail shortly after being placed in service on older cores, and it's always a good idea to put a new pull-off on as well, as the failure rate for them is pretty high as well.
One has to consider that those parts are often 30-40 years old!.......Cliff