Originally Posted By: 69GTX
I spent a lot of hours in similar engine bays back in the 1990's. Brings me right back to my B5 Blue 1969 GTX. What are you running for ignition on your Mopar? Mopar Performance electronic ignition? Pertronix? Or just plain old points and condenser? I still have a MP Electronic Ignition kit that I bought new in 1996 and never installed.
As close as those exhaust manifolds are to other components, I never had anything melt or fail due to them. I long for those days when you could change various belts, alternator, or a radiator in 30-60 minutes.
I converted it to regular Mopar electronic ignition many years ago, and right now I've got a "Rev-n-ator" aftermarket unit with a settable rev limit, but in a box that looks like a stock Mopar EI (
http://thertgarage.com/products.html). Its a little over priced for what it is since it doesn't have multiple sparks like MSD, but I've had some infant failures with the aftermarket EI boxes I've gotten in recent years and I like having a rev limiter. Unlike MSD, I can pop a spare Mopar EI box back in with a 3/8 wrench and a phillips screwdriver in about 5 minutes if it dies. Ever since the 70s I've always carried a spare ignition module and ballast resistor in the glovebox. Only had to use it a handful of times, but it sure beats walking!
The only thing that the manifolds have ever cooked for me is the valve cover gasket. I've tried the high-temp silicone gaskets with the steel valve covers, and the steel covers just flex too much to fully compress them and I always had to supplement with RTV, which itself would cook eventually. But these cast covers sealed right up with reusable Moroso silicone-over-steel gaskets and no added sealer or RTV, which was really nice.
Chrysler big-blocks are *wonderfully* easy to service in so many ways. 4 bolts hold in the water pump, which you can replace without removing the alternator/AC belts. Front distributor (yeah, the angle makes it just a little cramped, but not bad). "Dry" intake manifold so you don't have to drain the cooling system to R&R it. Deep-skirt block makes for a completely flat one-piece oil pan gasket without those pain-in-the-rear curved end pieces like smallblock Mopars (and Chevies) have. Oil pump mounted outside the block so you can swap it without dropping the pan.