i purchased some second hand agx shocks with sleeves and 450lb/350lb springs. installed them on the car as the came in the box and something just doesn't look right.
Measured center of the hub to edge of fender, 13 3/4in in the front and 12 1/2 in the back. there are no threads left to adjust down. so where is the problem?

 

Here's your problem...

 

Did you reverse the shocks?

 

not according to the way the old ones came off, long shock in the front shorter in the back. for some reason i feel like the springs are reversed?

 

Possible

 

Lower spring seats need to be removed. IIRC the top spring seats have to be modified too. Probably still needs bumpstops cut.

 

I have the same setup as the above and see your problem. You are running the coilover collars on top of the shocks spring perch. This is incorrect. That spring perch should be removed ( you can hammer it off, or pry it off ), and then there is a small aluminum collar that replaces that for the coilover to slide down over, and thus the coilover sits about an inch lower than they currently are.

Hope that makes sense.. Personally I had this problem a few years back and didn't have the little aluminum collars that I'm talking about. I ended up taking the 2 parts to a machine shot to have the perches made.

 

Best way to remove without damaging the shock?

 

They should come off with very little effort. I believe i just tapped them on opposite sides until they broke loose, then I pulled them off by hand.

I know there's a writeup on this somewhere online, I had the same issue when I went to install mine and was left clueless, then found some kind of article iirc.

 

Smack 'em with a hammer. They're just pressed on and tacked.