The Carter AFB/Edelbrock type carb doesn't like more than 4-5psi.

Manifold doesn't make much difference.  Excessive pressure will just push past the needle and cause it to flood.

Well, dumb me should have done this in the first place...  Get out the Owner's Manual and read it. "At idel no more than 6.0 psi, 5.5 with an adjustable fuel regulator.  At WOT it should not drop below 2.0 psi.

A Holley will handle up to 7 psi with no problems.

Oh well, I've got an Edelbrock and I've had good luck with them.  My 460 has just a mild build on it.  Thanks for your information Crewchief.  It is appreciated.  Now to find new fuel lines.  I saw some blue push on lines I like.  I may put clamps on them anyway.

Here's what I've got:

I don't trust any fuel connection without a clamp.

Me neither!!!  I don't care how low the pressure is.  So all connections will be clamped.  I sure as hell don't want a hose coming off and spitting fuel everywhere.  That's just 

hope your not trying to build hp with that thing

Only 450 is all.  Nothing to race, just have fun with. I didn't buy it for broken parts all the time.  I've had enough of that with the first go around.  Now everything is just about new and should be reliable.

just curious i had two of those carbs and gave them away.the sucked so bad

I've had Holleys that I threw away.  I wouldn't have wished the troubles I had on any one.  They had more vacuum leaks than I could ever seal up.  This is my second Edelbrock and no problems so far.  I guess everyone gets a lemon now and then.

guess so only thing is i had two 650 lemons and an 750 lemon.never again.id rather run a rochester 2 barrel.but thats me

DAMN!!  can you still find those things?   

I guess everyone has their preferences otherwise there would only be company to buy from.  This was an interesting video.

Nothing wrong with either carb.

Holleys - Easy to tune, pretty forgiving on tunes, most horsepower, quickest throttle response. Power valves that blow out, choke setup not as clean. Quick to adjust and tune.
Carter AFB - More mid range tunability, no power valves, backfires won't hurt them. Acc pump not as good, air door hurts power. Many parts to take off to tune.
Carter TQ - Big secondaries for power, little primaries for great throttle response and good cruising mpg. Large fuel bowls. Plastic body keeps fuel cool but can crack and leak after time.  Many parts to take off to tune. Parts getting hard to find, may not be able to tune perfect due to jet and metering rod restrictions (you can get close).
Rochester - Big secondaries for power, little primaries for great throttle response and good cruising mpg. Small float bowl shared by all bores (better have a great fuel system). Most complicated carb to tune or adjust.