I have a donor motor from a 93 LX 5.0L Convertible and running EFI. I need to know if this is HO or Non-HO as this factor decides which firing order to use. Either:

1-5-4-2-6-3-7-8 (Non-HO)
1-3-7-2-6-5-4-8 (HO)

63772d1344963247-firing-order.gif

I've tried both and neither sounds real good, alot of back-fire in the passenger exhaust.