well got a built motor and all jsut a 346 with ross pistons and such still stock rods but with the ARP rod bolts and all its tuned for motor but built for a 150 shot the car was tuned dead on 13:1 AFR well i got the tnt f1 kit and timing tuner and a wideband o2 to monitor af so how woudl i adjsut AF if it was to go too lean imma start off with 75 shot and prolyl end up leaving 100 hp jets in what an adjustable Fuel pressure regulator do the job if so cany any1 reccommend one also what kinda air fuel ration would i want on nitrous

 

Your pulling fuel off the rails right? It would be easiest just to swap fuel jets to do your tuning. TNT doesn't sell every size fuel jet but NX jets work fine. I always aim for around the 11.2 on the bottle.