Measuring Drive shaft
 

I just put a th400 into my 84 firebird and I need a new drive shaft for it, I looked in the knowledge base on how to get the correct length by measuring from the center of where the cup goes on the rear yoke to the center of the front yoke where the cup goes. Now after I get that measurement what is the correct way to measure the actual drive shaft at the wreckers?

Thanks

Not quite sure I understand your question just measure the same way at the wereckers. If you are having one made or cut down just subtract .750" from that measurment unless you have a lot of suspension travel then subtract 1".
Hope this helps. :thumbup:

install a front yoke and pull it out 1" measure from center of U joint cap to center or rear cap. Use this measurment at the junk yard or give it too the driveshaft company making one for you.