The issue with headers, equal-length tube headers, is their many twists, turns, and curves until they get to the collector, which might or might not be up close to the floorpan. By a bit of contrast, many "block hugger" or similar current headers are not nearly so "equal-length tubes" as they used to be. In that respect, they are simply tubular exhaust manifolds with better flow due to their smoother interior surfaces, I suspect. In the case of many OEMs, they also do not absorb needed heat to get the cat converters fired off quickly on a cold start situation. I suspect TTI's products are in that more middle-ground of thing?
In many cases, back then, headers were never really easy drop-in installations. Even on the popular Chevy small block applications, there was usually some strong words, use of a ball pein hammer to "clearance" some tubes, and holding your mouth right to get them to bolt up to the cyl heads before it was all over. And the supplied gaskets were very low quality, so they leaked and blew-out, no matter what you did to prevent those things, except getting better quality gaskets.
Most of those things were considered "part of the deal" if you wanted headers AND some didn't find out about them UNTIL the time of installation. Like "Oh yeah, you've got to . . .", PLUS whatever you had to do to clear the steering system and trans linkage, too. And, all brands were not the same in getting them installed, so asking around saved some time and efforts in getting them installed.
What I was a bit surprised at was how the engine in my friend's '79 Corvette ran after getting a set of thick-tube/flange headers put on (himself). Throughout the entire rpm range, throttle response was cleaner and the engine sounded happier whether it was at 1000rpm or 5000rpm. Getting a better scavenge, even at low rpms, works best. AND, once the headers were installed with the reinforced gaskets and better bolts that did not loosen, they were quiet and durable. Just getting "there" was the trick.
In the Chrysler realm of things, the B/RB and LA HP exh manifolds were close enough to headers (in power production) that adding headers was for the more hard-core people than not. Especialy as they just bolted in with few other issues. So, "we got spoiled" unlike the Chevy people, it seems. THEN, for the 1990s LT (no dash) 1 (reverse flow cooling system) 350s, Chevy did a great copy of the Chrysler B/RB HP exhaust manifolds on that engine. Just they hid them under 2 layers of heat shielding. Such a deal!
From my observations,
CBODY67
