what exactly is z'ing? i have a 89 gmc s15 and ive heard you have to z them to lay frame, right now im practically laying crossmember with the front bagged and air shocks in the rear any info will help, post pics too.
i zed my 74 C10 with the cab on and engine and tranny in, pretty simple, put 4 stands under the front( like a table), made the cuts, lowered the back of the truck3" and welded it back together (img)http://www.layitlow.com/forums/uploads/post-5326-1115540981.jpg(/img)
I did my Z with the motor in too. It helped me see that the distributor was going to hit the firewall so I moved the engine forward for more clearance and since I was swapping my manual 3 speed for an automatic I just got a longer tranny so my driveshaft would still work.