You
but the amount of time it took me to make mine, i would happily pay for a manifold off the shelf. I also spent weeks contacting brakers in the us trying to get an alliance manifold but with no luck
Making the manifold is probably the hardest part of EFI on a gtt, we have scoff making timing sensor brackets and with these two parts it would take no time at all to do a conversion. The rest of the required parts are just standard parts that everyone uses to convert to efi.
If only this was two years ago