20v into 85

[VOLK]

hi there. I have used search but didnt find the answer.
I have an 85 and next week im planing to get 20v silvertop for it, the problem is i dont want to bash my firewall to use original dizzy.
i plan to control my eng with LINK ecu, so i can use aftermarket cam shafts. And that gives me abbility tu use coil packs instead of dizzy.
But the question is what should replace the dizzi with?
Do i use the 4a-gze crank angle sensor, If so what do i do to make it fit?
4a-ge dizzy and 4a-gze crank angle sensor seems to have different pulleys.
Or can i pick up the signal from the dizzy's base, without the dizzy cap?