on my buddies truck. i built his motor using a stock volume oil pump, i don't really like a high volume pump with a stock pan. installed it in his truck, has great pressure, 60 all the time with the stock ('77) mechanical guage (30 at idle when warm). he ran dinosour oil. we ran that till the tranny blew, always had good pressure. then he bought a 81 k20 and put in the motor on this truck. we took the stock mechanical to keep a eye on it when we were working on the other stuff. he changed the oil putting synthetic in it and we got a 3 guage pod with mech temp, volts, and mech oil. now when we start it when its cold it shows 60 then it drops down to about 4 psi at idle when warm and will not go above 20 psi when revved. it is a sunpro guage set. we pulled the line off at the guage and it came out slow at idle. the line doesn't look to be pinched. could it be that the line is too far in the guage or the block and not letting flow by? could it be the synthetic oil? or could it be a faulty guage? hes not very knolagable when it comes to mechanical things, like working on a truck. and he wont take my advise alot of the time, like when i said to get autometer guages. hes a pesimest also, thinks everythings gonna cost him $3000 to fix, like when i said the ball joints won't come out and said he would have to buy a new housing and it'll cost $2000 /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif, he went nuts. /forums/images/graemlins/screwy.gif /forums/images/graemlins/screwy.gif anyway, any ideas on what to check, i don't wanna take the whole motor apart to find it was a bad guage or something.