Crew cab driveshafts

[Joey-T]

Anyone know the measurements for the two piece driveshafts in a crew cab. I am working on an 88 (square body) and have a 350 with a turbo 400. I wish I could tell you what the driveshafts came out of, but I can't- I just grabbed them from my pile of parts.

Here's the problem- the intermediate shaft goes into place- it fits in the tranny just fine and the carrier bearing lines up where it's supposed to. But the rear shaft- it fits the splines if the intermediate shaft and bolts to the rearend just fine, but it is just barely on the intermediate's splines... I'd say the intermediate is only in about an inch. Not good.

I can't tell you anything about the driveshafts, other than they are GM. For the intermediate, I had to get a special U-joint to mate it with the t400's yoke. It had the deal where you have to melt the plastic out to remove the joint. The back shaft isn't like that. In fact, the two shafts might not have came from the same truck, who knows. Also, the truck is at factory height. Anyone have any info/advice?

[Joey-T]

OK, I measured the rear driveshaft (from u-joint center to center) and it is 54 inches. I have on hand a 55 inch shaft and a 55.5 inch shaft.

I'm guessing that there is some geometry at work that will tell me that an extra 1.5 inches in length will not equal 1.5 additional inches on the spline, right?

Another question- when everything is right, I should not see ANY of the spline, right?

[Joey-T]

I finally got ahold of a Hollander, and it says the shaft is supposed to be 57.25 inches long. So I guess I'm back to looking for a shaft.