[HTC One V] Curtis1973:
Extract the following files from a compatible CDMA Rom (meaning if your gsm rom is ICS,use files from a version of ICS that does exist on the CDMA side..Jellybean,etc)

Open the gsm rom you wish to convert in winrar and navigate to each folder listed below and drag the file listed into the folder listed. be sure to delete its counterpart example: sensors.primou.so will be deleted,sensors.primoc.so will be dragged into rom. when prompted by winrar for compression method,select store. and let it add the file to the rom.

in system/lib/hw copy:

sensors.primoc.so

in system/etc/permissions copy:

android.hardware.sensor.proximity

android.hardware.sensor.light

android.hardware.sensor.acceletometer

in system/bin copy:

sensorservice

now the above will take care of sensors that use auto rotate,etc..

now to fix mms/sms

sense based roms usually have a file in framwork-res.apk called apns.xml,its in the xml folder within framework-res.apk. Copy the file from any stock rom or cdma rom that has the proper apns.xml you need into the gsm based rom you want mms/sms to work in. I use winrar to open the framework-res and simply navigate to xml and drag the file in and select store as option for compression.

now the mms/sms fix will usually be a little different in slim,cyanogen,asop,aokp type roms..but sometimes it isnt. only way to know is check. if the apns.xml isnt in framework-res or if it is and it does not contain the appropriate settings,check system/etc in rom for a file called apns-conf.xml and replace it with one from any cdma rom that is available that matches your rom..example would be my slim conversion. i used the apns-conf.xml from aokp because slim gsm and aokp are both 4.1.2 roms. just drag it into rom with winrar using the store compression setting. sometimes,but not always you can use some of these files on roms not of the same type like for instance 4.2.2 roms MAY..may..work with some files from 4.1.2,etc..its a trial and error kind of thing. try them out and see how it boots.

edit build.prop and change default network type to 4 instead of 0(there are other changes you can make to build.prop but i cant tell whether or not they have any effect so i will skip those).

you may encounter roaming notifications in some roms you are trying to convert. i tried two miui roms that are 4.1.2 based and encountered the roaming icon in status bar even though i had working connections..couldnt figure out how to get rid of the roaming indicator. also of note,after getting the rom up and running you may see "evdo" listed as your connection in status bar. you are 3G,just that some roms call it evdo..just rename the 3G icons in systemui.apk to the names of the evdo ones and they will show as 3G again.

now for the boot.img. if you are using ics sense roms,jmz's boot.img will work,you can try out sick kernel for roms that use that on the cdma side or any other kernel on the cdma side that will match the rom you are trying to use. for instance..slim gsm to cdma uses the aokp kernel from the cdma side. be sure to add the system/lib/modules files to the rom and if the rom does not even have a modules directory,add it with appropriate files from your kernel. if you plan on sharing the newly converted rom with the public be sure to get proper permissions from all those you used source material from.

i know its not a perfect guide and rough around the edges but should get you running.