Manifold questions

Many years ago,I put a 69-340 top end on a stock 73Dart, low compression teener, and there was no saving that turd. With the stock low-stall TC and 2.76s it was a disaster.It was a slug off the line as compared to the factory 2bbl top end.The power didn't come on until about 40 mph,and then the stock cam gave up. But hey it had pretty good passing power.....at 80mph. Or at least it sounded like it did. So I did the obvious, I put the 340 cam in it. And that took it from bad to worse.
On that very same teener short block;many more years later, and now wearing its factory heads and cam, I tried something else. I put headers on it,a TQ, 3.55s and a 2400TC. I also installed a wide-ratio 904.Now pushing 3850 pounds, it was a whole different much funner car. (The 73 Dart was long gone to the shredder).
So, I know you didn't ask;but
If you wanna perk up the teener may I suggest gears and a higher stall TC, plus a 4bbl, on the stock long block. And of course dual exhaust. It will be waaay more bang for the buck.Waaay more. At least 3.55s and at least 2400. And I love TQs, and so do teeners! A pair of Treblegs Bigmouth exhaust manifolds would be icing on the cake! But I wouldn't be in a hurry to change them out with the teener heads, 2.76s, and duals. And the reason is cuz, the gearing is so bad (11.2mph per 1000rpm),that first gear is good to about [email protected] the teener iron manifolds can probably breath most of the way there. And then you hit second gear for a bit and you're done.And if you go with 3.55s and a 2800TC, the teener will be much more lightly loaded in first gear, and still be ok for most of that gear. Now, headers that's a whole nuther story. Most of the time headers is the number 1 very first thing to install.
So if you are on a budget;gears,TC, and dual exhaust.Oh yeah put some springs on those valves to get the Rs up to at least 5200. 5500 is better.If you can swing headers, I would do those waaay before 340 heads, planed or not.And I would put a good used 360 cam in there still before heads. Cuz those big-valve heads need taller pistons.
Ok so that's what I earned.