The car is a 1990 Towncar 5.0l. When I bought this car last saturday it had a serious lack of power and I figured the timing was off and it would be a simple fix.
So I checked the timing and it was more than a few degrees off 10btdc. I fixed that and then checked the wires and a few of them differed from what the sticker on the fan shrowd listed. I fixed the order to what the shrowd listed which was 1-5-4-2-6-3-7-8. This made it idle and run horrible. I got backfires and very low power. So I started looking around online and found the firing order for a H.O. 5.0 mustang motor ( 1-3-7-2-6-5-4-8 ) and gave it a try. It runs flawlessly now.
What all has to be changed to use the HO firing order? I don't know if the motor is a full ho long block or just the cam or what. What can I check to see how much of this motor is a HO?