Its still a little confusing. I reckon that the A15 will end up costing more that buying a ca18 or similer to get it technologically the same (efi, crank angle sensor, turbo etc) , since I have to rebuild the A15 to suit, and a low k jap import shouldnt need a rebuild yet since a standard one would be more than enough to start with at this stage.

Its the installation that is the question. Will it cost the same to install the a15 as the ca?

Its the install that I dont know anythng about.
I have to go custom exhaust anyways for both
move engine mounts for both
new raditaor for both
move the battery box for both (larger radiator and neateness)
new clutch for both
new diff for both
new prop shaft for both since 60a 5speed is planned.

I expect that the ca would cost more, but is it significantly more?