Standard proceedure w/n20 on a carbed car is set up the car w/o nitrous and then subtract 2 degrees for each 50hp of nitrous. If yur car runs on 32* total advance @3000rpm and you run 150 shot of n20, you should run the timing at 26* total advance at 3000 rpm. That's a place to start anyway.
Skip
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Michigan Skip's Flamed 95
95Z28, K&N TPIS 150hp NOS & 27mpg!
MSD 6AL, Window switch,Ford SVO 24# injectors,
2.73's (3.42's to come) Edelbrock headers, Flowmaster exhaust
BMR SFC,LCA,STB