2500 RPM Engine knock

[mcbride66coupe]

I figure this is a stupid question, but I don't know the answer and you have to learn some how so here it goes. I just got a mustang that I purchased running two days ago. It has set for close to a year. The 302 was rebuilt roughly 2000 miles ago. I changed the oil, flushed the raditor, and swapped the holley carb out for a 600cfm edelbrock performer with vacuum secondaries. It idles at 800 rpm's with the vacuum reading 15. I can rev the engine to 3500 rpm's while in park and everything sounds great. Whenever I am driving, if I push the pedal 3/4 the way down it will start to knock. Anything less than that is fine but once you push the pedal 3/4 or to the floor it knocks until you back off. Any help on ridding the knock would be greatly appreciated.

Thanks

 

[1966conv]

What's your timing set at? It sounds like predetonation under load (or pinging)
Did you change the fuel?
If it sat for a year or so, did you pre lube it?

It could be a whole bunch of things, some good and easy to fix, and some baaaaad. The easiest being the fuel and timing. The bad being no lube and spinning/cooking a bearing.