To answer a few questions:
Yes, these engines (all big-block Mopars) originally come with a pack of foil-wrapped insulation under the intake and above the valley pan, but it is purely for sound deadening- to muffle the noise the lifters make. The exhaust heat crossover is *above* said insulation, and removing the insulation and partially (or totally) blocking the crossover will cool the manifold better than leaving the insulation pack there and just blocking the x-over. The factory manifold *is* an "air gap" style on big Mopars, its not like small Mopars where the hot oil touches the intake underside. The insulation pack blocks airflow under the manifold, though.
As to what causes the v-lock- its boiling in the carb on this engine, and as I've said its only a warm day in winter thing when they switch us over to the high vapor-pressure fuel for "better vaporization" during winter months. Summer is *fine* even though the temps are much much higher under the hood. No amount of heat shielding or insulating the carb from the manifold with phenolic spacers has stopped it yet, and the exhaust crossover pumps a lot of heat into the carb through the mounting studs. The fuel line is completely insulated, and I'm running a rear-mounted pusher electric pump so the line never even gets close to the engine until it hits the carb. Short of installing a closed-loop system with a regulator and return line like my '69 has, the fuel is as cool as possible until it touches the carb.
As for the wisdom of blocking the X-over... I ran the previous engine (the original 383) for about 10 years with the x-over completely blocked. Trust me, there's *no* negative effect on driveability in my climate. Even in freezing weather (which is about as cold as it gets here), the manifold warms quickly by conduction from the heads, especially since I'm running the aluminum Mobil 1 dual plane. Plus the charge air temp is lower so I can add a few more degrees of ignition advance without pinging.
Sorry, I didn't shoot any pics of the cam... didn't really think about it since it looked perfectly good. The rockers, shafts, valves, springs,cam, and pushrods look clean as the day I built it. I'm very pleased with the Rotella so far, but as I said 30k miles really isn't much of a test. The one exception would be under the valve covers near the outside edges- big Mopars really heat that area up because of the upswept "log" exhaust manifolds and the exhaust crossover passage directly inside the head. Most older conventional oils will carboinze or "coke" a little at that area, but it was perfectly clean with no hint of charring with the Rotella. Same as I've seen on other BBMopars with Mobil 1.
Thanks for all the comments, and next time I wind up doing a job like that I'll shoot some photos for sure. What I really wish I had were photos of my wife's old '93 3.5L when I replaced its valve cover gaskets at over 200k miles- SPOTLESS clean. That was on Mobil 1 10W30, SL rated and prior though.
