Power loss above 4000 rpm

[hotrodhomi]

what is the total advance at?

[TurnNBurn]

I had just about the same prob on my 79 K20 , i would get into 4th, 4 speed manual, stand on it and it would fall on its face and slowly drop off. If i let off for a second then hit it again it felt like pullin it down a gear and jumpin on it. it would blast off. I stared replacing parts, I had a clear fuel filter
so i seen that, fuel pump wasnt keeping up, but I only could see it if i stop on the road and look. idling it was full. so i replaced the pump no good, so
took off the gas line and blew threw the hose and ha ha, it was just about pluged. I dropped the tank and changed the pick up screen in the tank. problem solved (the gas line could be cracked and sucking air too) worked for me , good Luck hope I could Help