what would i have to do to my heads to run a vs cam with 1.8rr??

i know most would say take the 1.8s out and get a bigger cam, but well i like the power curve of the vs and im one to work with what you got. plus i think it would be a pretty cool set up.

stock cam lift is 400/408.
1.8s yeild 450/459.
vs cam 512/507 with 1.6.

another question is what would my lift be??

any takers on this???