help,can't remember dash voltage regulator

I just finished the wiring for an electronic voltage limiter
nte capacitor 20v 100fd 25u ROHS about 80 cents
Transistor 15v to 5v about $1.00
heat sink about $1.20 or so...including tax, $3.60..
here in Cal
I'm double checking on the connections though... can't make a mistake
a voltage limiter from autozone for a 74 dart..is $37.00
best