4x4 not engaging, 1990 1500

[silveroddo]

Hey everyone, I've got a 1990 chev, reg cab long box auto 4x4, I just put a new rear main in and after putting it back together the 4x4 is not engaging at the front axel, the transfer case engages but as far as I can tell the front end isn't locking, I havn't had the chance to put it in the air to check it out yet, hopefully tomorrow I can do some further investigating, It looked like all of the plugs were connecting but I need to double check all that, before I did the rear main the 4x4 worked fine, it did want to lag a little on engagement, I.E. it took a second to fully enagage or you might have to shift it from reverse to forward to get it to click, but I've seen that quite a bit on these older trucks. Any info?
I'mnot totally sure how the front end works as far as locking, a friend of mine was telling me about a kit that locks the front end all the time then when you engaged the transfer case there wasn't any lag time, just looking for some ideas, info,and maybe a better understanding of what I'm dealing with here.
BTW if it matters its a 305 and a 700R4. Thanks for looking, any info is appreciated.