I have a '92ish 4D56 in my 87 Raider(auto) ...when i had my injectors rebuilt i did a Comp test and got readings of 395 to 410psi ...what are good readings? ...also my oil pres. will say close to 40lbs on startup cold then drop to 20lbs hiway cruising and 5psi at a warm idle ...unknown milage on the motor as i bought it in Thailand and shiped it over ...i reprofiled the turbo and put in a 13G spool ...running 2 1/2in 316 stainless exhaust all the way back ...ditched the top mount IC and put a large front mount IC in (dropped EGTs by 250*F) ....turbo has very little lag and will build 21psi boost very quick (at 3000ft elv)...just turned the pump up 1/2 a turn and get a small amount of smoke when you first punch it ...but now my EGTs are a bit higher (1100ish post turbo) the truck pulls like mad and can do 100km/h up any 8-10% grades here in BC without kicking the OD off (no auto kickdown) running 33/10.5 KMs ...i'll soon be building a 3" stainless snorkel and do some dyno runs to see what kinda power i'm making...i'm just worried about my low oil pres ...haven't found a source for a new oil pump yet ....anyone?

I can't answer your questions, but your post makes me want to ask you a ton of my own! Very nice! No other upgrades to the engine other than Turbo/IC and turning up the pump?

Well i have 2.5" stainless exhaust (wanted 3" but have to do a body lift first) and i have a cone filter ...i will be building it in a box and then a build a stainless snorkel
...my turbo is just reprofiled with a 13G spool put in
...pump is turned up 1/2 turn from stock ...no real smoke yet