:D Hi mate, do you know the type of oil they used to put back in your engine because if its 10/40s or simmilar semi sythetic, this oil is to thin and if your valve guides are slightly worn you may not have noticed in the past due to you or previous owners useing other oil.
Try Duchams 20/50s this is much more better than modern semi/synthetics and does not tend to leak through/passed the oil rings in your v8 or the valve seals, but if this works your best of changeing the oil more reguarly than normal.
I used in my 3.5 V8 15/40s semi the dear stuff a while ago and altough it started better in the mornings once the oil was at running temp the oil pressure dropped off dramatically, and like your self a phew weeks later there was a hint of smoke appearing from exhaust in the morning on startup because oil was leaking past the vavle gear due to its thinness, once ide changed back to 20/50s the oil pressure returned back to normal 35/40 psi on idle 50/60 psi when pushed. And i noticed it didnt blow iol out on startup and little oil leaks around the engine itself dissapeared.
Hope this helps.
Cant think what else could be causeing it, unless by shere coincidence your valve gear has gone all of a sudden ( very doutfull ). :?
