i recently dropped the wore out 305 tbi and put in a rebuilt 350 tbi it runs great the other day i put flowtech short headers with two and half inch exhaust with a flowermaster. i cut the a/c box out just leaving the blower motor after driving it i turn the heater i hear the blower motor running but no air into the car so i covered the hole in the firewall left by the a/c . now i am not getting nothin the blower motor isnt even turnin plz help its cold and i would like some heat

 

Blower motor is in the box that you say you cut out/off. If you removed the box from the firewall, and covered the hole without replacing the box with an A/C delete box that has another blower motor in it, you have no blower motor at all for any fan operation.

If you rigged up something different (which I don't know how you would have), you'll need to get us pics to understand exactly what you have done, because right now it doen't make any sense.