[Sony Xperia Z Ultra] reaper61616:
I suggest you to wait for ftf and then try to flash... Also prepare your stock rom ftf (not zip - new radio for 4.3.A so probably you will not be able to connect to network). Don't know about bootloader... And when you download ftf start from flashing kernel only and see if it will boot.

STILL I'M NOT SURE IF FLASHING FTF FROM C6833 IS GOOD IDEA - DON'T KNOW DIFERENTS BETWEEN C6802 AND C6833 IT MAY DEMAGE YOUR PHONE!!!

My build.prop from 4.3.A:

##### Merging of the /util/data/semc_kernel_time_stamp.prop file #####
ro.build.date=Thu Feb 20 12:57:13 2014
ro.build.date.utc=1392897433
ro.build.user=BuildUser
ro.build.host=BuildHost

##### Final patch of properties #####
ro.build.product=C6833
ro.build.description=C6833-user 4.4.2 14.3.A.0.681 Vv1_jg release-keys

ro.product.brand=Sony
ro.product.name=C6833
ro.product.device=C6833
ro.build.version.incremental=Vv1_jg
ro.build.tags=release-keys
ro.build.fingerprint=Sony/C6833/C6833:4.4.2/14.3.A.0.681/Vv1_jg:user/release-keys

######################## Customized property values #########################
ro.semc.version.cust=1275-9426
ro.semc.version.cust_revision=R3C
ro.somc.customerid=463

#############################################################################

############## Product Property Values ##############
ro.setupwizard.mode=DISABLED
#####################################################

ro.config.ringtone=xperia.ogg
ro.config.notification_sound=notification.ogg
ro.config.alarm_alert=alarm.ogg
ro.semc.content.number=PA36

################# Updating of the SW Version #################
ro.semc.version.fs_revision=14.3.A.0.681
ro.build.id=14.3.A.0.681
ro.build.display.id=14.3.A.0.681

##### Values from product package metadata #####
ro.semc.product.model=C6833
ro.semc.ms_type_id=PM-0410-BV
ro.semc.version.fs=GLOBAL-LTE
ro.semc.product.name=Xperia Z Ultra
ro.semc.product.device=C68
ro.product.model=C6833

# begin build properties
# autogenerated by buildinfo.sh
ro.build.version.sdk=19
ro.build.version.codename=REL
ro.build.version.release=4.4.2
ro.build.type=user
ro.product.board=MSM8974
ro.product.cpu.abi=armeabi-v7a
ro.product.cpu.abi2=armeabi
ro.product.manufacturer=Sony
ro.product.locale.language=en
ro.product.locale.region=US
ro.wifi.channels=
ro.board.platform=msm8974
# ro.build.product is obsolete; use ro.product.device
# Do not try to parse ro.build.description or .fingerprint
ro.build.characteristics=default
# end build properties
#
# from device/qcom/msm8974/system.prop
#
#
# system.prop for msm8974
#

rild.libpath=/vendor/lib/libril-qc-qmi-1.so
rild.libargs=-d /dev/smd0
persist.rild.nitz_plmn=
persist.rild.nitz_long_ons_0=
persist.rild.nitz_long_ons_1=
persist.rild.nitz_long_ons_2=
persist.rild.nitz_long_ons_3=
persist.rild.nitz_short_ons_0=
persist.rild.nitz_short_ons_1=
persist.rild.nitz_short_ons_2=
persist.rild.nitz_short_ons_3=
ril.subscription.types=NV,RUIM
DEVICE_PROVISIONED=1

debug.sf.hw=1
debug.egl.hw=1
debug.composition.type=c2d
persist.hwc.mdpcomp.enable=true
debug.mdpcomp.logs=0
debug.mdpcomp.4k2kSplit=true
dalvik.vm.heapsize=36m
dev.pm.dyn_samplingrate=1
persist.demo.hdmirotationlock=false

ro.hdmi.enable=true
persist.speaker.prot.enable=false
qcom.hw.aac.encoder=true
#
# system props for the cne module
#
persist.cne.feature=1

#system props for the MM modules

media.stagefright.enable-player=true
media.stagefright.enable-http=true
media.stagefright.enable-aac=true
media.stagefright.enable-qcp=true
media.stagefright.enable-fma2dp=true
media.stagefright.enable-scan=true
mmp.enable.3g2=true
mm.enable.smoothstreaming=true
media.aac_51_output_enabled=true
#37491 is decimal sum of supported codecs in AAL
#codecs: AVI AC3 ASF AAC QCP DTS 3G2 MP2TS
mm.enable.qcom_parser=37491

# VIDC: debug_levels
# 1:ERROR 2:HIGH 4:LOW 0:NOLOGS 7:AllLOGS
vidc.debug.level=1
#
# system props for the data modules
#
ro.use_data_netmgrd=true
persist.data.netmgrd.qos.enable=true
ro.data.large_tcp_window_size=true

#system props for time-services
persist.timed.enable=true

#
# system prop for opengles version
#
# 196608 is decimal for 0x30000 to report version 3
ro.opengles.version=196608

# System property for cabl
ro.qualcomm.cabl=1

#
# System props for telephony
# System prop to turn on CdmaLTEPhone always
telephony.lteOnCdmaDevice=0

#
# System props for bluetooth
# System prop to turn on hfp client
#bluetooth.hfp.client=1

#Simulate sdcard on /data/media
#
persist.fuse_sdcard=true

#
#snapdragon value add features
#
ro.qc.sdk.audio.ssr=false
##fluencetype can be "fluence" or "fluencepro" or "none"
ro.qc.sdk.audio.fluencetype=none
persist.audio.fluence.voicecall=true
persist.audio.fluence.voicerec=false
persist.audio.fluence.speaker=true

ro.qc.sdk.gestures.camera=false
ro.qc.sdk.camera.facialproc=false
# system prop for NFC DT
ro.nfc.port=I2C
#property to enable user to access Google WFD settings.
persist.debug.wfd.enable=1
#property to choose between virtual/external wfd display
persist.sys.wfd.virtual=0
tunnel.audio.encode = true

#use VERY_HIGH_QUALITY for audio resampler
af.resampler.quality=4

#Buffer size in kbytes for compress offload playback
audio.offload.buffer.size.kb=32

#Disable offload audio video playback by default
av.offload.enable=false

#enable voice path for PCM VoIP by default
use.voice.path.for.pcm.voip=true

#disable dsp gapless mode by default
audio.offload.gapless.enabled=false
#
# from device/somc/rhine/system.prop
#
#
# platform specific part of system.prop
#

#System prop for gralloc
persist.gralloc.cp.level3=1

#System props for audio
persist.audio.hp=true

#System props for the MM Audio
media.aac_51_output_enabled=true

# system property for somc thermal solution
ro.somc.thermal=system_monitor

# Enables two core touch boost
sys.somc.touch_perf_kick=1

#System props for the MM modules
encoder.video.profile=high

# aDSP sensors
ro.qualcomm.sensors.qmd=true
debug.qualcomm.sns.hal=w
ro.qc.sdk.sensors.gestures=false
ro.qc.sensors.max_accel_rate=false
ro.qc.sensors.max_gyro_rate=false
ro.qc.sensors.max_mag_rate=false
ro.qc.sensors.smgr_mag_cal_en=true
ro.qualcomm.sensors.pedometer=false
ro.qc.sensors.step_counter=true
ro.qc.sensors.step_detector=true
ro.qualcomm.sensors.pam=false
ro.qualcomm.sensors.scrn_ortn=false
ro.qualcomm.sensors.georv=true
ro.qualcomm.sensors.smd=sony

# Default values/Locales for the hiding languages feature
ro.product.locale.excluded=ar_EG ar_IL fa_IR iw_IL

# Do not use mdp composition for more than 3 pipes
debug.mdpcomp.maxpermixer=3
# Disable mixed mode
debug.mdpcomp.mixedmode.disable=1

# Modem power save enabled
persist.radio.add_power_save=1
#
# from device/somc/togari/system.prop
#
#
# product specific part of system.prop
#
ro.usb.pid_suffix=19C
ro.zygote.preload.configs=sw540dp

# NFC
ro.nfc.on.default=true
ro.nfc.se.sim.enable=true
ro.nfc.se.smx.enable=false
ro.nfc.icon.enable=false

#
# ADDITIONAL_BUILD_PROPERTIES
#
ro.product-res-path=framework/SemcGenericUxpRes.apk
ro.com.android.dataroaming=false
persist.sys.logkit.ctrlcode=0
keyguard.no_require_sim=true
ro.com.android.dateformat=MM-dd-yyyy
ro.carrier=unknown
ro.vendor.extension_library=/vendor/lib/libqc-opt.so
persist.radio.apm_sim_not_pwdn=1
ro.com.google.clientidbase=android-sonyericsson
ro.com.google.clientidbase.ms=android-sonymobile
ro.com.google.gmsversion=4.4.2_r1
dalvik.vm.heapstartsize=8m
dalvik.vm.heapgrowthlimit=192m
dalvik.vm.heapsize=512m
dalvik.vm.heaptargetutilization=0.75
dalvik.vm.heapminfree=512k
dalvik.vm.heapmaxfree=8m
ro.sf.lcd_density=320
ro.hwui.texture_cache_size=48
ro.hwui.layer_cache_size=32
ro.hwui.r_buffer_cache_size=4
ro.hwui.path_cache_size=24
ro.hwui.gradient_cache_size=1
ro.hwui.drop_shadow_cache_size=5
ro.hwui.texture_cache_flushrate=0.5
ro.hwui.text_small_cache_width=1024
ro.hwui.text_small_cache_height=512
ro.hwui.text_large_cache_width=2048
ro.hwui.text_large_cache_height=1024
persist.sys.dalvik.vm.lib=libdvm.so
dalvik.vm.dexopt-flags=m=y
net.bt.name=Android
dalvik.vm.stack-trace-file=/data/anr/traces.txt
ro.qc.sdk.izat.premium_enabled=1
ro.qc.sdk.izat.service_mask=0x0
persist.gps.qc_nlp_in_use=1
persist.loc.nlp_name=com.qualcomm.services.location
ro.gps.agps_provider=1
ro.service.swiqi3.supported=true
persist.service.swiqi3.enable=1
ro.drm.active.num=7
ro.drm.active.0=marlin,1
ro.drm.active.1=playready,1
ro.drm.active.2=dtla,1
ro.drm.active.3=marlin_import,1
ro.drm.active.4=ckb,1
ro.drm.active.5=widevine,1
ro.drm.active.6=dcp,1
ro.sony.fota.encrypteddata=supported