pinion ?

how do i figure my pinion angle, with the frame all the way on the ground should my rear end be straight or should it be angled down some? I know i can adjust it later with the four link but i dont want to weld all my link tabs in and them be to far off to adjust? Here is a half ass pic of what i got 

your supposed to set it at half travel, but i would measure it at ride height with a magnetic degree wheel. can be found at home depot/lowes etc.

Pinion is never set with the frame on the ground, its set at ride height, usually around 4-5" off the ground. Youll need an angle finder to measure the angle of both the pinion flange and tranny output shaft. The pinion should equal but opposite of the tranny, within 2°. So if the tranny is pointing 3° down, the pinion should point 3° up, or anywhere between 1-5° up. If you have a 2 piece shaft then youll have to contend with that issue. The easiest way is to set the first shaft at the same angle down as the tranny, but off 1-2° to allow the u-joints to grease themselves. Then follow the same procedure as before.

Thanks guys this helps alot!