Pre crossflow on roller rockers

[Precrossflowlover]

Hi  This is my first post on here  Would kindly require your help. Have a pre crossflow on 40 s and bcf3 cam. Car war impeccable though I decided to add some more lift by fitting 1.69 rockers but car has gone mad and I'm really lost whether I do have an ignition timing issue or the actual engine timing requires to be retarded due to the higher lift rato. Engine was at 15 deg initial retarded each 2 deg till 6 deg tested but do not believe its ignition related. Is my thinking correct that the engine timing require retarding ? Is it a push rod length issue ? Or a 3d ignition issue. Engine is now stalling after 3000 rpm Your help is appreciated

[Graham]

rocker change wont of changed ignition timing requirements.

are your valve springs now going coil bound?