When you swapped carbs, did you also swap intakes? If not, you didn't attempt to re-use the base gasket from the Holley, did you? It would explain your vacuum leak, or at least part of it. People always try to re-use those thick gaskets; it should never be done, particularly when changing carb designs as the various vacuum passages on the bottom of the carb vary wildly between carb makes.
The gasket you should be using is as 68R/T described... with today's crappy fuel you want some heat insulation under the carb. Fel-Pro makes it (I stock it) but I don't know the number off the top of my head. Also, per Edelbrock, you want the four-hole variety, not the open-plenum design. Edelbrock's reason for this is an improvement in velocity and fuel atomization. If you want to run a thinner gasket, there's a GM part number for a factory gasket/heat-shield combination gasket used on old Corvettes. Someone else makes it as well--I was surprised to see it in one of my catalogs, but I can't recall who it was at the moment.
Actually, with an electric choke I'd suggest blocking the heat crossover entirely at the cylinder-head/intake mating surface. Since you won't be winter driving, you'll never miss it.
Regarding the kickdown linkage's angle: Even with it all the way back at full throttle, I think the angle's going to affect your line pressure at part throttle. It might be slight, but I'd really rather see that sucker level as is factory. Even though some upward travel is normal with the linkage on a factory setup, with your angle involved it's still lifting more than it's pushing in the right direction for some of the throttle's travel. I think I'd have lengthened that C-shaped pivot rod at the back of the throttle slider, spaced it, or heated and bent the throttle slider before I would have welded and redrilled it.
Kickdown linkage has always been a nightmare for Mopar guys with aftermarket intakes. Yet another reason I love manual transmissions.
Seriously, the geometry of that linkage is critical to both the proper operation and the longevity of the transmission.
Clunk: did you put new motor mounts in the beast? The driver's side motor mounts are notorious for tearing. It might be the engine jumping around. Freddy broke several LH motor mounts in his '74 318 Trout when we were kids (it was a pretty-hot 318, but still...). I tore no less than 4 in my Six Pack Charger. DynaTech's MityMounts are a great investment; I was never able to break one in The Black Bitch, and I beat that car like a rented red-headed step-goat. They're only sold in pairs and I think I still have the right-side mount new in the box. I never installed it, just put in the LH side and was golden. They're not inexpensive, but they're well worth the price. EFI Ed's not broken one on his stroker-engined beast and the same set's been in that car since '97.
Redline: this is a 340? I used to pound my 340 cars, shifting them as high as 7,800RPM without ever hurting either one. 7,200RPM was my normal shift point on my '73 Charger with 135,000+ miles--going by my AutoMeter tach. I was a little more gentle with the '73 Challenger--that one I think I shifted around 6,800RPM after I learned it was still pulling like a freight train well after the factory-indicated redline of 5K. One thing you have to remember: the factory redline was dictated by the fact that even Hemi cars had a powertrain 12/12K (months/miles) warranty. Everything else was 5 years/50K miles... if you tell the new owner the engine will scream to 6,500 he's gonna try it, enjoy it, and repeatedly do it.
If your trans shifts by itself anywhere between 5K and 6K, you're fine and the governor doesn't need to be replaced. If it's below 5K, the governer's lo-performance passcar or more likely truck stuff and should be replaced.
One thing to remember about non-shift-kit Torqueflites: under full throttle, they consider a change of shifter position more a suggestion than a command.
They do
not respond instantaneously. My experience with them tells me they shift anywhere from 500-800RPM higher than when you moved the lever. Bashing the Slap Stik in my '73 Charger 340 at 6,600RPM was how I got it to shift in the neighborhood of 7,200RPM. They're all different, though... you have to learn your trans. A shift kit, flinging the accumulator spring, and upping the line pressure to max will get you a transmission that's screeching the rear tires before the Slap-Stik's ratchet action even lets off. Of course, you need a properly-functioning kickdown linkage for that to happen, too.
without a tranny rebuild-at least for now) Rich.
Rich.
Rich.