exhaust manifold stud mystery

patrick · Post by **patrick** » Wed Sep 10, 2008 12:55 am

I have '70-'71 casting Hi-Po exhaust manifolds on my '73 RR. I removed them many moons ago for sandblasting, flapper removal, brazing, and hi-temp coating. Now I can't remember... What are the two little studs for poking out of the driver's side manifold? I'm debating whether I need to order new ones since I need to order all new exhaust mounting bolts anyway since the previous owner Mickey Moused EVERYTHING. Maybe they're not used for my application, but it's driving me nuts what they are for.

For a picture of what I'm talking about, you can go to rtspecialties.net and type in the following:

EXHAUST MANIFOLD STUD B/RB ENG

I have no affiliation with them. This is for reference only. Thanks.

471Magnum · Post by **471Magnum** » Wed Sep 10, 2008 7:44 am

The two little studs on the driverside are for the mounting of the heat riser.

The heat risers are now being reproduced.

patrick · Post by **patrick** » Wed Sep 10, 2008 9:46 am

471Magnum wrote:The two little studs on the driverside are for the mounting of the heat riser.

The heat risers are now being reproduced.

I know about the flapper valve on the passenger side (because I removed it, LOL), but can't for the life of me think what a heat riser is on the driver's side. I remember back in the late '80s, my first car, a '72 Charger with a 318, had this little flexible metal tubing thing, is it something like that?

Point is, I'm just going to omit the screws altogether then since I live in Southern California and have a manual (cable) choke anyway. Does this sound feasible?

72RoadRunnerGTX · Post by **72RoadRunnerGTX** » Wed Sep 10, 2008 11:45 am

The two studs on the drivers side manifold are to mount what was commonly referred to as a heat stove. A sheet metal covering over the top of the manifold that had a hose fitting that connected to one of the snorkels on the air cleaner. A vacuum controlled flapper in the snorkel would divert pre-heated air from this stove to the carb on a cold motor. Nothing to do with the heat riser system at all. If you are not running the factory air cleaner you can disregard the stove and studs.

471Magnum · Post by **471Magnum** » Wed Sep 10, 2008 12:54 pm

Sorry. Wrong choice of terms. Heat stove is correct.

Unless you are running a factor silences/snorkle aircleaner, you've got no use for this.

71440 gtx · Post by **71440 gtx** » Wed Sep 10, 2008 2:27 pm

471Magnum wrote:Sorry. Wrong choice of terms. Heat stove is correct.

Unless you are running a factor silences/snorkle aircleaner, you've got no use for this.

the 70 -72 b-body air grabber with hemi 400 340 383 440 4bbl 440 6bb cars do not have heat stove

and 71 440 6bbl non air grabber hood

72RoadRunnerGTX · Post by **72RoadRunnerGTX** » Wed Sep 10, 2008 3:18 pm

For model year 1972, the â€œFresh Air Packageâ€ (Air grabber) was not an option for any big block cars built for sale in California. The heat stove system was considered part of the equipment necessary to meet California emission standards that year.

Note the 340 is not listed as N/A for the Air Grabber in California.

Found some on-line retailers referring to these heat stoves as heat risers as well, easy to mix up the terms.