First, as you've noted, DUMP THE E-CARB! You're not the first, nor the last, to complain about them. The Q-Jet is FAR superior.
"Spark knock" is dangerous to the engine. Unless "steps" were taken to lower static compression, it's not spark causing the pinging, it's detonation, and it's KILLING your rings and pistons. 9.5:1 is tha absolute limit for static compression and 93 octane gas. I know... Others "successfully" run higher. No, they don't. Oh, maybe SOME, but for the most part, they simply retard the timing to take the ping out, which also takes out "the power" and significantly increases cylinder temperatures. And it really does little if anything to prevent detonation. Reducing compression or increasing octane are the only SURE ways of getting rid of this issue. Using a cam with more overlap is also a poor way to approach the problem. While it DOES "bleed off" cylinder pressure at lower engine speeds, it does NOTHING at higher engines speeds. "Time" is your ONLY "ally" up high, and sometimes, it isn't enough. We've seen MANY engines damaged by detonation, and the owner said "I didn't hear a thing!" Yet, the rings fall off the pistons in pieces when they're removed and ring lands show damage, as well.
As for getting the power "back" after reducing compression, we (CVMS) have found the Comp XE series of cams to be unequalled. I know, there ARE "nay sayers", but none of them are professional engine builders. Virtually every builder I know and/or talk to, agrees, for lower compression, XE cams can't be beat. And if your budget can "stand it", the XE rollers are INCREDIBLE! Avoid the "urge" to alter the specs, LSA in particular. Comp knows their product better than anyone else. The "tests" I've read where the XE grinds didn't perform "as expected" ALL had some parameters changed, usually LSA. Beware the tester. They will alter conditions prior to the "test" to assure the desired results, even if that "desired result" is a negative report.
As for lobe "failures" (heading this one off "at the pass") on XE grinds, well, we've installed no less than 100 of these cams in the last 10 years, and have lost a total of ONE lobe in an engine WE "ran in", and one on a customer's that HE "ran in". In both cases, we're at a loss to explain why. We have also lost one lobe on a Crower, even when using Rhoads lifters, which I was assured by the guy that "set up" the heads, it would "never" happen. Never say never... We no longer take another's "word" that heads are properly set up, we disassemble them and measure.
I believe one of the main reasons people have cam failures is they refuse to "follow instructions". When the cam grinder says to remove the "inner" springs for break-in, REMOVE THE INNER SPRINGS! Pop always said: "When all else fails, follow instructions!" I don't "buy" the oil thing being bantered about, either. We use Rotella T for break-in with no additives. Of course, we use a high-pressure lube on the lifter at install. Also, one of the main "points" for that argument is that all modern engines are "rollers", and that simply isn't true. VW, Nissan, Toyota, even GM, use "buckets" as cam followers in many of their engines, which are no different than flat-tappet lifters, except they act directly on the valve instead of going through a rocker system.
