Ok guys i really need your help. I purchased this 88 Mustang 5.0L HO engine a while ago. At the time of purchase it was running real nice. I put on a new weiand dual plane intake manifold (originally had a single plane edelbrock streetmaster) and replaced some parts on the holley 650cfm carb it was running with before, mounted it to my C4 and put it in my 67 mustang. Its running with the same fuel pump/electronic ignition/wires/carb, everything but the intake manifold and now that its in my car im getting some serious engine knock. Any suggestions?

 

how is you timing? you might have adjusted the timing while removing and installing the distributor when you put on a new intake manifold.

 

I didn't take the distributor off when putting the new intake on, but i think ill hafta check the timing anyways. would changing the intake manifold affect the timing at all? would a bad ignition box cause this problem? also when i try to rev above 3000 the rpm guage will jump to 4500 and the engine seems to die off or something, but when i ease off the accelerator it still runs fine, just not above 3000.