Gen 2 Hemi, heat riser or no heat riser in manifolds?

[Nxcoupe]

I am going to be buying new hemi exhaust manifolds and I am not planning on running the heat tubes up to the intake, but I want it to have a factory look still. Wondering what the brain trust thinks? I may just remove the flap so the outside looks stock and am using a flat plate to cover the flange hole on the manifold. But do those tubes really affect drivability? I didn't use them on my 71 hemi cuda(not original), but that was 40 years ago, I can't recall how it drove.
Any inout is appreciated.

 

[Bird 426]

Well, yes, it's going to run different until it gets up to driving temperature. It will be a little on the lean side.

 

[Runcharger]

Don't worry about it. Chrysler designed the Street Hemi to drive in all kinds of weather right down below the freezing range. On a hobby car any slight reduction in cold engine driveability won't be noticed. I drove them for close to 40 years and I don't think I ever had the heat tubes hooked up.

 

[Jerry Hall]

The heat tubes perform great to get the engine to operating temperature. I know most have heard some Hemi owners say, it cranks and runs like Grandma's grocery getter. This is why. Of the Hemi's that I own, one is temperamental and it's the one with headers and no heat tubes. It takes about 5 minutes of keeping above 1200 rpms to get it to 160 degrees, where it will then idle and not go dead when put into gear. For me, I would keep them fully functional. I don't think they deter performance in any way when functional.

 

[gtx6970]

I've driven them both with and without.

Once adjusted. They both ran fine
In all honesty...the best street hemi I've ever driven is a buddy's 1970 hemi AAR clone. And on that car. They are they...but made non functional.
But it's a 474 FHO stroker...so I'm sure that's a factor

 

[gtx6970]

Ps. Mine has them and they are functional.
And it can be a little cold natured

 

[Bird 426]

Didn't know that there was ever a Hemi AAR. Yeah, I know, just had to say that.

 

[AR67GTX]

My heat tubes are functional but the heat riser flap is gone. The choke is functional but a little slow to respond. It idles pretty rough on startup which I think is due to a rich, over-choked adjustment. If you have a fairly warm garage these cars don’t really need much choke as it just makes them overly rich and the combustion is poor. At least in my opinion. I’ve leaned my choke out some but haven’t had much chance to drive it lately. Once fully warmed up it’s smooth.

 

[mrhemi]

I have driven mine for over 40 years with no functional heat tubes nor choke. Just a certain number of cranks and accelerator pump strokes and it fires right up. Have to let it warm up a bit, but never an issue. Now, mine is kept in a climate controlled shop so that helps. My carbs are stock and setup as per the FSM with the exception of the choke settings. Since repro exhaust manifolds were not available when I completed my Charger back then, I removed the shaft and damper and replaced it with a bolt to allow the counterweight to be installed and appear correct. Like I said, been there 40+ years.

 

[mrhemi]

I should have included a potential "heads up" depending on what path you chose. I originally had NOS heat tubes installed for appearance. They were blanked, so no heating function. The mistake was blanking the return tube at the rear of the intake manifold as that was easier. Since that configuration left the tube exposed to the exhaust, it eventually corroded through (at a most inopportune time) causing a severe exhaust leak. So a new method of capping at the H-pipe was employed with removal of the tubes. Recently I replaced the NOS factory exhaust with a repro system from Gardner. They offer options for the heat tube connection on the H-pipe. I chose to have the nipple installed, but not bored through. This is the proper way to blank the tubes should I want to install a set in the future for appearances.