408w running poorly

[rwhite65]

Just finished installing the Edelbrock Victor Jr's on the 408 last week and have been trying to get it to run right this week. The car ran good before the install (boo too me), but did not have the power the owner wanted.

I am in the process of timing it, and also should have some vacuum readings within an hour or two. I know until I have the timing down, all this could be hard to diagnose, but humor me here.

When I took it for a drive, the darn thing felt real sluggish. So much, that I turned right around and parked it. It will be idleing at 1100 rpm's and jump up to 2100 all on its own. It will stay there for 5-10 secondse, then come back down to 1100. If you are trying to feather the throttle, the 1st quarter of throttle feels dead. That first quarter feels like it does nothing, unlike before the head swap. Give it more then a 1/4 throttle, and she revs right up, but seems to be slow at coming back down.

Standing at the rear exhaust, I swear I can hear a miss in it, but have checked the firing order several times, the plug wires are on good, and the plugs are brand new.

Checked the oil, looks and smells good. Tried spraying w/d 40 around the intake and carb gasket areas....made no difference. I am really thinking I have a gasket leak, most likely at the intake. Any guesses?

408w, 750 double pumper, msd all around, Comp Cam #35-250-4 , Weiand Stealth intake, shorties to 2.5 out the back.
Thanks as always guys.....I am really begining to hate this 408!
Ryan