Need help with drive shaft after engine/tranny swap

[68jimmy]

Well I finally swapped out the original v6/3-speed in my 68 gmc lwb to a 350/350 combo. The engine is located in the forward position and the tranny has the shorter 6" tail shaft. Now to the problem, I went to install my fron drive shaft and discovered that it is about 3" inches to short. If anyone has done a similar swap how much was needed to be added to to the driveshaft length? Or was the yoke from a similar setup longer? Or was there a front driveshaft made specifically for the v8/350 combo that is longer? If so does anyone have a length that I should be looking for? I could go rummage around one of the local yards and see what I find...

thanks.