Guy in my industrial complex does allot of EFI conversions, for a crank signal he's adopted the Ford strategy of a toothed wheel with a tooth every ten degrees but with one tooth missing to ID TDC of #1 & 6 cylinders... It's referred to by Ford a 36 minus 1... He sandwiches a 36 tooth bicycle sprocket with one tooth removed between the harmonic balancer & the crank pulley.... He still needs a Cam sensor but as mentioned all it does is tell the computer whether cyl 1-8-4-3 or cyl 6-5-7-2 is on compression stroke..