L98 short block with addition of vortec heads, spreadbore edel, TBI adapter w OE TBI and 74#/hr injectors. Started on stock tbi swirl head peanut cam tune. Did a plug and play '747 swap in place of oe '299. Only change to bin was to address larger injectors. Sent bro home and within an hour he's texting me that it's backfiring. Google searched vortec spark map. Cut and paste spark map into bin. Bros immediate response during the datalog capture drive...I can feel the difference. Cleaned up the VE and have not revisited spark.