The dual curve support unit will "fool" the computor into not setting a code and turning on the light and allow you to reset the timing. The Impco CA300 is a bit small for a 460 but will work fine on a 302. Impco makes adaptors so that you can splice them into the air intake ahead of the throttle body. I have work for LP equipment Distributors in the US since high school so I fall into the habit of saying "Contact your local LP dealer" due to liability, if you can find the equipment and feel comfortable installing it, Go for it

Good Luck