I'd not be keen doing a tune on a secondhand fuel pump or injectors. Too expensive if anything plays up. A weak pump has been the cause of many wasted hours tuning for weak top end AFRs.

The hassle of fitting an engine or something over the relatively low cost of a fuel pump and a set of injectors.

While I am on the soap box, please steer clear of the cheapo K04s. Some people have done OK but plenty of others haven't. Especially if you want to go for all the power.

Gavin