To do a valve adjustment you will need to remove both valve covers. While they can be taken off with the intake manifolds in place its tight work getting the cover bolts out. You need a flexible extension or u joint to get at the upper center bolt, not easy but doable. To avoid any chance of rain, I would work in a garage if possible. If you live in Denver there are indoor parking garages all over town. For $10 or so you should be able to work all day.
OOps missed the Orlando location
------------------ " THE BLACK PARALYZER"
-87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 07-03-2015).]