[Rick Parker]

Unfortunately all the Ford Engine installs in most Cobra Chassis that do not utilize a remote filter mount end up with either the use of an undersized filter or one that is very difficult to access. Best option is to carefully plan a remote filter location. Barring that, the nipple that the filter screws onto CAN be shortened to allow for a longer filter to inserted between the frame member.

Here's How:

Measure how many full threads the filter can has in it (this will vary by brand of filter). Engage threads in filter and screw it on the number of turns so the nipple threads are engaged fully, then measure carefully fronm the filter gasket to the block mounting pad, this dimension is how much can be removed from the nipple itself. By doing this you may be able to find a longer filter that will fit, or at least allow for a little more room to install existing filter and for fitting wrench to install or remove. It's not necessary to overtighten when installing.
You can also get creative by using a GM Sourced 13/16 thread filter and machine and weld together portions of each mounting nipple. There are aftermarket filters such as K&N #3002 that is sized between a Ford full size FL1 and Ford's popular FL300.