transfer case info needed and have noises

[melmount]

If swapping a transfer case from another truck what has to match? Whats the ratio mean? Does it have to stay the same? I know diff ratios must match. I have 410's. I have no electric shift, would my manual shift bolt to the electric shift location?

I know sometimes when engaging 4wd it may slightly clunk when putting it in 4wd. Maybe its not supposed to but thats never bothered me. I have been chasing a clunk and feel I have it narrowed down. I moved the truck around the other day with the rear drive shaft removed(different reason) Its too heavy to push, so i engaged 4wd high and used the front diff to turn it around. When putting it in reverse I get a loud clunk. Going in drive was ok.
Since then i have finished my rear end install and rear driveshaft. I am getting a clunk from reverse to drive now. I am back in 2wd. At first I was thinking rear diff issue. But I am fairly convinced its a tail shaft noise.
Any way to confirm its a transfer case?
how interchangable are the transfer cases? dont want one I cant use.
thx

[HVAC SuperTech]

dont know, but I did have a slight clunk when I engaged the auto 4wd on mine. but thats before my trans rebuid. after that, I have not heard the clunk. just swaps right in.

heres a BUMP for ya.

[melmount]

if i remove the rear driveshaft at the trans flange, then put it in gear, if its in the transfer case would it still clunk? The driveshaft may be neccessary to put the load on the transfer case?

[HVAC SuperTech]

hows your u joints? and Carrier bearing?

[melmount]

u joints and carrier bearing are new. I have seen new parts that are defective before.
Last nite after using the truck all dayi got under it. I swear it was coming rom the tailshaft area. Rear end was quiet. But this morning I could not tell from where again.
Hows the back of the tranny connectedto the driveshaft.?? I mean the connection at the trannys tail? The transfer case is what? male spline right?Then whats the rest like til it hits the driveshaft flange? Whats spinning in the transfer case that could clunk when in 2wd not 4?
I have a huge transfer case clunk if in 4wd(no rear wheel drive shaft installed) just using the front and putting the gear shifter in reverse.