I've read thru a bit of this manifold heat stove discussion.
This is lengthy - so not intended for casual readers, but only those for whom the heat stove holds interest.
I will be putting some 'trust' that some of these pics I paste are accurately attributed to the year/carline, but my logic I believe will align with it.
I'm not knowledgable on the post-July-1972 aspect.
Feel free to correct me if I'm wrong -- I'll gladly edit anything I post that is incorrect, in the name of future reference.
Some things I believe I can call 'facts':
Heat stoves started for the C-bodies (likely A-B-E, too) in 1970 as only the 1970+ rectangular snorkels had provisions for the flex-tube. '69-older oval snorkels did not have such provisions.
The '70 TNT manifold had features cast-in for heat-stove use: heatsink fins, a 'lip' at the area where the front of the stove was located, and bolt bosses. (this heat stove was 1-piece)
I'm 99% the only features cast-in for the standard 1970 log
manifold were the bolt bosses. (this heat stove was 2-piece)
-->> From an engineering perspective - the fins on the HP manifold helped it shed heat into the 1-pc stove, while the 'smooth' log manifold likely needed more surface area and therefore more encapsulation, perhaps that's why it was 2-piece)
While I'm 99% positive that 1970 log
manifolds only had bosses cast in, I am less sure when the later log manifolds got 'stiffening' ribs cast in them.
1971 would be my guess, as my youthful car-crossing had me attain some 1971 engines, but no 1972+ bigblock engines. (and I still have some ribbed manifolds, so I believe they came from the 1971s I had gotten). But regardless of that, I've not seen 'the lip' cast into any log manifold (Formal manifolds are not in consideration here).
And the pics from @73Coupe
in post #94 for a 1973 manifold fits my beliefs on the lip. And he noted his took a 2-pc stove.
The 1972 Chrysler Thread
Whether the 1972 manifold has the lip is up to @saforwardlook
to confirm? (if 72 has the lip, it's a 1-year manifold?)
In addition to 'the lip' being introduced in 1970 for the HP, the 70-71 HP's heat stove is installed rearward
of it. (my reason for focusing here on 1970 manifolds is related to the reproduction part mentioned by @ayilar )
Can you advise if this manifold in post #97 has a cast-in lip hiding under the stove?
IF it has the lip cast into it, it might debunk my theory on the LHS vs RHS FSM sketch noted earlier. But would mean a 1-year manifold for 72, or a 72-74 CA-only manifold (neither of which makes financial sense)
Also - any idea what the red circle might've be used for? Looks somewhat like an unmachined feature that was used for a manifold-to-aircleaner emissions tube used on right-rear of mid-late 70s 318s.
SO - my theory:
Not being familiar with what FSM this sketch is from, and not seeing the rest of the manifold, I think this snip might represent a log manifold on the LHS and an HP manifold on the RHS.
Note the red mark in my snip, I believe this is to represent the 'lip'. The blue line also suggests some curvature - yes it's mild, but the LHS clearly depicts a straight edge, yes?
And the RHS bolts are noticeably longer, and the stove change wouldn't seem to require longer bolts?
- Is there more to this sketch? Does it show the RHS manifold in its entirety? If so, can you post the full size of it?
It'll either confirm my thought or show I'm FOS. (I'm OK with either outcome)
My 1970 FSM clearly depicts the HP heat stove as 1-piece and with 3 bolts holding it onto the manifold,
1 on top and 2 below.
And the stove is quite short (front-rear) compared to the log manifold stove - the outlet to the air cleaner is between cyls #1 and #3, rather than near #1 for the logs.
(refer to Detmatt's pic on the 'red boards' further below.)
From my wanderings, the 70-71 HP C-body heat stove is HTF and IMHO nobody is going to reproduce it - there's no ROI for it.
It's an uncommon manifold for 70-71, and I believe it's not not used on any
C-body in 72+ unless it's a copcar? (and even then, it stopped in '74?)
Pic below credited to @detmatt
So, with that said, I believe the FSM sketch shown earlier is depicting an HP manifold for a B (and E?)-body
due to the apparent curvature in the sketch.
I further think it is for a '72-74 HP manifold, but with the lip thru the bosses not being accurately depicted.
I would believe the artwork would've been verified for 1-pc vs 2-pc, while the long lip might escape the drawing checkers? In addition, the stove outlet is clearly toward the front of the manifold vs the 70-71 C-body 'short' stove (although the angle isn't quite right).
See this pic of this dark-gray manifold #3751068 for '72-74 B&E body. Based on the long lip that runs thru the mounting bosses, I believe this would take a 1-pc stove.
I haven't confirmed a stove to match it, but here's a potential, part# 3751175 noted below.
I believe the reproduction stove would fit this manifold noted to be for 70-71 B+E-bodies, which does NOT have the lip running thru the bosses. (it might happen to fit the '72-74, though, but would be coincidence) The repro stove is noted for 70-71 383-440, so that fits my logic noted here. 70-71 383-440 HP Left Exhaust Manifold Heat Stove | Roseville Moparts
My theory on the FSM sketch is unconfirmed as of now.
My 1 conclusion:
My 1970 FSM and Detmatt's pics clearly shows 3 bolts holding the stove on, so the reproduction item noted will NOT be suitable for @ayilar
's 70 TNT (sorry @Ripinator
The correct stove for 70-71 will be HTF and might require buying a whole manifold to get it.