Drive Shaft Cut

I did the recommended (Mopar Muscle Magazine & A-Bodies Forum members)- 69 Barracuda rear axle up on jacks, slid the shaft in until it bottomed out on 727, pulled out 1.5 inches then measured from centre yolk to centre yolk on 8 3/4. I came up with a measurement of 44 inches.

But, when i took it to my reputable driveline shop, they said that 1.5 is too much and that it should only pulled away from the tranny by 1/2 inch, then measured.

What do you folks think? Is 1/2 play going to be enough with a 440 out in front of it all?