Originally Posted by delawarebill
rule of thumb.. use an angle finder on the trans on a flat spot. like the pan. find that angle then set the finder on the flat part of rear input of U joint and tilt it up that same number.. so in your case the trans is down 5° the input of rear should be 5° up.
My thinking through the years has been to leave a degree or two between the two, so that as power is applied to the tires, the pinion will rise a little and the two angles will be very close together. Like, if the trans shaft is 3 degrees down bubble, I might put the pinion in at 1 degree up bubble. Like I said, under power, the pinion will climb the ring gear and the two should be pretty close to equal.