A search didn't turn up any answers to this topic even though I'm sure it has been discussed in the past.

Anyway, in regard to a hot air tube (aka heat riser tube) between the exhaust manifold shroud and the air cleaner snorkel for 455's:

1. Any differences in length/shape between years 70, 71, 72?
2. Any differences in the tube for OAI vs standard air cleaner assembly in 1970?

Incidently, I have 2 spare tubes for a 350 cid and both are too long (tall) for the 455 cid.

 

You wouldn't have a spare bracket that the heat tube sits in, the one bolted to the exhaust manifold, would you?

// end hijack.

 

Mike PM answered.

 

Fusick sells them aftermarket for $99. Its a nice reproduction piece that fits well.

 

After doing some searching, I'm going to resurrect this thread instead of starting a new one on the same topic. Now that I am gathering parts to get the hot air tubes set up for my '70 SX 455 and two '72 455 cars (a task that is way overdue!), I'm finding interesting discrepancies. Maybe we can aggregate some good info and pics here. I'll post a few pics here later this evening.

455 hot air tubes and manifold heat stoves/shrouds: 1969-70 tubes and heat stoves/shrouds have mounting holes at a 45 degree angle and use screws to mount. Interestingly, all of the reproduction shrouds appear to use this mounting pattern. That's great unless you have a 1971-72. These tubes and heat stoves/shrouds have mounting holes straight across from each other, and use a cotter pin to fasten them. That renders my two reproduction shrouds useless for my two '72s unless I drill new mounting holes.

The 1970 assembly manual looks to be straightforward for hot air tubes. The same page in the 1972 assembly manual is a real clown car with a bunch of different things listed. I've had a couple dozen of these cars since 1990 and I'm going to have to study and decipher what it's referring to - not just for the A-body 455s, but there are references to and diagrams for B and C cars with N10 dual exhaust conversions. Why is that in the Cutlass/442 Assembly Manual?

I'm interested in sorting out the various tube lengths for the 1972 455 4 barrel, the same engine with OAI, and the 1970 L-3 455 2 barrel in A-bodies. We can cover 350s here as well for those who have or need that info.

I'll be posting pics of the four tubes I have now so we can all discuss and learn something new.

Terry

 

Assembly manual pages from 1970 and 1972. Appears that the pipe is the same for all 1970 455 A-body applications (4 barrel with and without OAI, and L-33 2bbl.) 1972 pipe also appears to be the same for any 1970 455 A-body applications.

 

Any time I hold these up to each other, it's like a Jedi mind trick and some appear about an inch shorter than the others, but lining them up like this shows they're pretty much the same length and part. I have one 1979-70 pipe and three 1971-72s here.


1969-70 slots at an angle vs. 71-72 holes straight across.


Reproduction shroud for 69-72+ but with only 1969-70 mounting holes.

 

Great info and photos, Terry.

And this is just for you - which one is longer?

 

Terry I have a slightly used reproduction manifold shroud without any holes in it if you want trade it for the one with the 69-70 holes. This way you wont have to drill new holes and have two sets in it.

 

As Terry said: "After doing some searching, I'm going to resurrect this thread instead of starting a new one on the same topic." Interestingly my pipe has the holes at 45º as in the 1970 version but they are round as in the style of the 1971 pipe. I found in other threads that some people also say the tube sits a little high which makes the passenger side of the OIA air cleaner not rest level on the carb. Anyone else have this issue or any solutions? I can probably elongate the holes on the tube or drill different holes in the shield. In reality, this is just another item I would never need as I don't drive the car in winter but it is something I wouldn't mind getting back together. Its been off the car so long I can't even find the metal screen that was on it (is not reproduced, or at least wasn't in the past) - and the screen you can't even see.

 

Steven, refer to https://www.fusickautomotiveproducts...?number=230725

Gary

 

Thanks, wow, I wouldn't think there would be enough of a market for a part no one sees or even needs.