It's going to tough to come up with an odd fire h.e.i. dist.there are some out there but be careful the problem is the firing spacing I ran into this about 30 yrs ago on a friend of mines jeep. When the went to the even fire they splay ground the crank to make the firing pulses even the crank pin is ground in a step unlike the odd fire where 2 rods are on the same throw I don't know if this has helped you but it is so hard to explain in words without drawing but there are 2 rods on each crank through bt the are offset ground to even out the timing spacing sorry I give up thing to explain ...ted