where can i tap into the my 88 formulas 305 tbi motor too temporarily hook up a oil pressure gauge

On the drivers side of the block just below the spark plugs there will be the oil pressure fitting which you should just be able to remove and screw in your own guage. You might have get an adapter if the new one isn't the same thread size but otherwise you should be all set.

or around 11 o' clock above the timing cover, or on the china wall near the distributor

i cant really see.....does the stock intake cover up that hole.....another thing....will my pre 85 edelbrock performer intake fit it this motor?

It shouldn't cover the hole on the china wall at all. I am going to switch and use the one above the oil filter. I have a real bad leak on the one by the dist.