v.ice1

Im new to the site but im familiar with it so trust me i have searched before i ask this question.i have a ls/vtec setup with the following

gsr head milled 40
crower double valve springs and tit. retainers
ctr cams
ferrea flat faces valves
ported b16 intake manifold( long but succesful story)
alfa werks 4-2-1 header
b18b1 block
b16 pistons
forged rods
ARP rod and head bolts/studs
ls crank
blockguard
block decked to 40
72 mm ford mustang tb
aem cam gears
timing belt $220
gsr water pump
type r oil pump
act heavy duty pp
stock flywheel
4 puck bronze solid
pr3 ecu tuned on crome

thats off the top of my head.the motor is a beast but after 2 or 3 pulls vtec stops working i think its because the oil psi drops i currently dont have a oil guage but im 100 % sure it is i was told that if i install a thinner oil feed line to the head it might solve my problem i was also told that there was a way to raise oil psi somehow in the oil pump but i dont know how to do so also im running 10w30 mobil 1 synthetic oil with a golden eagle conversion kit the oil pressure sending unit is gone..im in desperate need of help to solvethis problem plz help