I'd lock out the timing also. 85 and I both know a guy that had the mech. adv. come apart at rpm he hit the nitrous not knowing the adv. was messed up and broke 3 pistons and burned some valves85Camaro said:Lock out the mech advance in the distributor, and use a timing retard module to retard timing when starting the engine. If you get a multi stange retard module you can also use it to retard the timing when the nitrous is acivated....Remeber to reset your ign timing after locking out the distibutor and/or installing a retard module.