You can find 'em on most any early 80's GM truck. Take the distributor cap off, and it's mounte inside the dizzy, like the module on a Honderp. It's really your best bet, because if you use that stock module, you'll want it inside the cab cuz it's big and ugly, and not weather proof. The GM module however, IS fairly weather proof, and is very small. Also way easier to find than the '78 Datsun module. You can buy them new as well at any parts store ( $30-$50). The modules I have are garbage to me, you could have one for the shipping cost, I just can't emphasize enough you should go the GM module route. Let me know what you figure out.