Hey, I've been interested in an A/C blower motor block off plate too. Kind of a curious thing because if someone ordered an A/C car, why would it be blocked off? And if you didn't want A/C, you would simply not buy it. 40 years later if you buy an old car, it is what it is but if you're like me, for whatever reason you may not want A/C.
An A/C blower motor is totally different than the heat only, there's no ring that bolts to the firewall so you need to come up with a sort of triangular shape to accommodate the larger and differently shaped hole. It's frustrating that the firewalls are totally different too, you can't just get the circular ring and bolt it on.
I would love for someone with some fab skills (not me) to come up with a 'factory looking' piece. I've seen the CNC machined ones that 1fast383 was selling. Indeed, they are nice looking parts but I'd rather have a more OE type piece. Probably thinner sheet metal, no engraving or border and easily painted to look 'correct'. :dontknow:
I love delete plates, they just scream factory race car!