Headers vs. Manifolds – that argument has gone on for decades and will continue for more decades.
Headers will flow more air – but are noisier, leak more, can have rust issues, get in the way on some repairs, sometimes don’t fit well and sometimes hit speed bumps or other pavement issues.
Exhaust manifolds are quitter, will almost always fit and ongoing maintaince is rarely a concern (like tightening bolts. Leaky gaskets, etc.)
Personally, I like my cars to be quiet and as maintaince free as possible – even if I have a loss of power because of it. Also, I’ve worked on enough headers that I’m sick of them already.
To back up a bit, The Right exhaust manifold (cast # 2863549 - the one that looks like a flat “Y”) was used in ’68-70 A-body and ’70 E-body. The Left side manifold (cast # 2863553) was used from ’68-70 A-body and ’70 E-body (as well) – but also in ’71 (A, B and E-body) –
IF the air cleaner design used did not use the heated air from Left side manifold (aka: used the fresh air system, instead).
The 340’s that used a conventional air cleaner uses a heater duct on manifold to heat the air to aid with cold weather drivability. The ’71 and newer 340 Left manifolds (with conventional air cleaners) – look the same as older ones – but has extra bosses cast in to attach the hot air (stove) tin. The ’71-72 Left side still flows about the same, only looks slightly different.
The ’71 and newer Right side looks more like a log style and just don’t flow the same.
In ’73, the Left side got smaller, as well.
That pair of exhaust manifolds are being repop’ed and is available from Year One, for about $700 (US). I would hang onto yours if you are not planning on using them (in other words, don’t toss them away).
I’ve got a rusty pair sitting in my garage and just waiting for me to install ‘em onto something.
The pair of cylinder heads flow the same as all 340/360’s (with 1.88” intake valves) from ‘71ish until the magnum engines came out in 1992. Installing 2.02” intake valves into your cylinder heads will net better air flow (the same as the ’68 to ‘71ish “X” or “J” cylinder heads will) – but not as well as the Magnum cylinder heads do (1992-2003). It takes a bit to convert a small block to use Magnum cylinder heads – so if looking for more power – one would need to consider yours vs. aftermarket aluminum heads vs, Magnum changeover.
When Chrysler went to the A.I.R. injection system for emissions usage, they widened the flange on the cylinder head. They also drilled holes in that wider flange for the A.I.R. air ports. A person can’t use newer exhaust manifolds (about ’74 to ’93) on older cylinder heads without modification to emissions equipment or to exhaust manifolds. Your cylinder heads have the wider flange, but no holes drilled (which is rare) – so it will fit all LA small blocks from ’64-93 (not Poly and not Magnum) – which is a big plus. Also, I assume that the bigger valves have been installed, if someone had ported your heads. Not something to write home about – but are still very usable heads (almost trouble free).
View attachment 30584
318 (has smaller intake/exhaust ports than 340/360) with A.I.R. holes drilled
View attachment 30586
Your wide flange but without A.I.R. ports drilled
View attachment 30585
Older 318 with older smaller (not as tall) exhaust flange.
As far as I’m aware, all F-body non-styled wheels came from factory painted “black” – but don’t quote me on that (as soon as I say it is written in stone, I will be proved wrong . . .). That does include the police wheels, which also came in black. There is a slightly different version of the police wheel that came on Super Coups that were painted (Argent, I think ?) – but they do not have a provision for the small hubcaps to attach.
That said – it is your car and if you want to paint wheels the body color, I will not complain one bit – for honestly, I don’t know why they didn’t come that way to begin with (I prefer body colored wheels).
My plans for my wagon is to install 15” police wheels (in black) and use the small hubcaps – because I want to keep the appearance mostly stock (which is my preference). I also have plans on installing 11” rear brake drums and 11¾” front brake rotors – both of which will not work with 14” wheels (which are present), so replacement wheels are mandatory.
For my ’86 Fifth Ave, I will be replacing the stock 15” wheels with Police wheels – but they will be hidden behind the stock lockable wire hubcaps (to maintain the sleeper effect). I love the 5on5 and 10-spoke Mirada wheels – but they only came 15x6” – which is a bit narrower than I want to use (need wider tires, for the way I drive). There are a couple of venders still making police wheels new and will make to your specifications at a decent price ( . . . unless you are buying 10 of them at once (2 sets of 4, plus 2 spares), like I’m planning on).
I heard the 4.5x5 bolt pattern Rallye caps will fit the police (or regular) wheels – but have no first-hand knowledge there. Hopefully someone else can speak up, on that.
A833 transmissions: There are a few Aluminum cases out there (not a lot) – but most are cast iron (which is fine). The aluminum cases are troublesome anyway.
Almost all the tailhousings made from early ‘70’s is made of aluminum – which I would recommend installing (less weight – especially trying to heft it back in place).
There are two different length tailhousing – short (A, F, M and J-body) and long (everything else). The short tailhousings are completely interchangeable between iron and aluminum and there are no issues about strength or fitment. If your overdrive transmission has an aluminum housing – I would swap ‘em out before install.
The non-overdrive transmission will be a lot more fun to drive in town – but not as good for fuel mileage if planning on driving it a lot (which you said you will be).
Just make sure to change position of the front link if you are changing it between overdrive or back.
I visited my brother this weekend and he mentioned about looking for an adjustable pinion snubber for his race car. I don’t know if he has an 8¾” or a Dana in his car (which are different), but said if I found one for sale I’d let him know.
If you would send me a PM on your wanted price and I will relay it to him. Also, I would be interested in your driver quality small hub caps if/when you are ready to sell. If so, just send me a PM on it, as well.
BudW