I have a 1980  GMC C2500 3/4 2wheel drive>The motor has been replaced > The new motor is a GM remanufactored 454. I recentely purchased a new carb. A edelbrock 1400 performance series.

Will work with the 454 HD 7.4l engine. I think it is the replacement for the 350 that was stock motor when purchased

Also, they couldn't smog the truck, Because the shop told me that they

could not find a emmisions diagram for a 454 Hd with a EGR valve in their system.  Where would  I find a diagram. So, I can troublshoot, and get my truck smogged. 

Thank,( in advance), you!

well the carb is a 600 cfm i put one on my 454 and it wasnt big enough im running a 870cfm holly and down jetted a few sizes but my motor isnt stock you should use a 750 at least my opinion and the egr diagram just get a haynes manual looking at mine its in their hey good luck with it