Initial timing should be rougly the same as before install.
Being EFI the initial timing trigger is mechanically set in relation to the crank location(8 degrees advanced at TDC on piston 1)the advance will then be mapped through the ECU to get the best results for your combonation.Get it tuned on the factory ECU.
Hope this helps.
I think you will need a bigger stall convertor(rpm wise)to get the most out of the 286 equipped engine if thats what you are after.