Potato,
To save time and effort, pull the injectors on the cylinders that you said the GlowPlugs were damaged. Easiest check. This will get you right into the combustion chamber. If the tips still exist, they will be in there. The flame holes on the 84 were pretty small for good fuel economy.
There is a copper gasket that needs to be used when you install the injectors. don't loose the ones you have. New ones would be better.
HammerWerf
1999 k2500 Suburban Pyro, Tranny Temp, Boost, K&N Air Filter, +3.5 qt tranny pan. 190000 miles
1984 C20 249k miles DSG gear, SM-465, 3.73
1983 C30 CC dualie. 308K miles on Chassis, TH400, 4-45 A/C Looking for a TurboCharger