[C1] Exhaust manifold question
10-21-2018, 05:50 PM
#1
Exhaust manifold question
Ok, simple question. How can I tell if the 1958 exhaust manifolds I have are from a corvette vs a passenger car?
parts 3749965 , 3747038.
I assume are right part part numbers but did I read somewhere that impalas and passenger cars are same in 1958 but date code is two digit year? Or is that something I read about date codes on intake manifolds? I thought on intake manifolds there was no way of telling if it was the single carb cast iron one. Someone set me straight.
Thanks
parts 3749965 , 3747038.
I assume are right part part numbers but did I read somewhere that impalas and passenger cars are same in 1958 but date code is two digit year? Or is that something I read about date codes on intake manifolds? I thought on intake manifolds there was no way of telling if it was the single carb cast iron one. Someone set me straight.
Thanks
Last edited by Jason Conroy; 10-21-2018 at 06:38 PM.
10-21-2018, 08:22 PM
#2
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ALL 58 Corvettes used 3749965(L) and 3750556(R) exhaust manifolds.
When a 58 Corvette engine was equipped with fuel injection, neither the left nor right manifold did not have a heat riser tube inside the manifold. If a 58 Corvette had a carbureted engine, then the right manifold had a heat riser tube.
The right manifold also would have a bracket cast on the front with two threaded holes for the generator bracket, regardless of FI or carb.
The 3747038 manifold was a mid-60s right side manifold--------------------for pass cars WITHOUT a bracket cast onto the front for a generator bracket..
When a 58 Corvette engine was equipped with fuel injection, neither the left nor right manifold did not have a heat riser tube inside the manifold. If a 58 Corvette had a carbureted engine, then the right manifold had a heat riser tube.
The right manifold also would have a bracket cast on the front with two threaded holes for the generator bracket, regardless of FI or carb.
The 3747038 manifold was a mid-60s right side manifold--------------------for pass cars WITHOUT a bracket cast onto the front for a generator bracket..
Last edited by DZAUTO; 10-21-2018 at 08:33 PM.
10-21-2018, 08:42 PM
#3
ALL 58 Corvettes used 3749965(L) and 3750556(R) exhaust manifolds.
When a 58 Corvette engine was equipped with fuel injection, neither the left nor right manifold did not have a heat riser tube inside the manifold. If a 58 Corvette had a carbureted engine, then the right manifold had a heat riser tube.
The right manifold also would have a bracket cast on the front with two threaded holes for the generator bracket, regardless of FI or carb.
The 3747038 manifold was a mid-60s right side manifold--------------------for pass cars WITHOUT a bracket cast onto the front for a generator bracket..
When a 58 Corvette engine was equipped with fuel injection, neither the left nor right manifold did not have a heat riser tube inside the manifold. If a 58 Corvette had a carbureted engine, then the right manifold had a heat riser tube.
The right manifold also would have a bracket cast on the front with two threaded holes for the generator bracket, regardless of FI or carb.
The 3747038 manifold was a mid-60s right side manifold--------------------for pass cars WITHOUT a bracket cast onto the front for a generator bracket..
http://www.nastyz28.com/sbcmenu.html#exhaust
and if I’m reading that correct they both used those two part numbers you just gave. And if they did is there a way to tell the difference? And I cannot find on this forum about the date codes being different but it may not have been on this.
10-21-2018, 08:49 PM
#4
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Yes, the pass cars would have used the 965 and 556 manifolds. They were sort of universal manifolds for any Chevy engine.
A single digit for the year on the casting date denotes that the engine came from Flint and 2 digits for the casting date denotes that the engine came from Tonawanda.
Corvette engines ONLY came from Flint.
A single digit for the year on the casting date denotes that the engine came from Flint and 2 digits for the casting date denotes that the engine came from Tonawanda.
Corvette engines ONLY came from Flint.
10-21-2018, 08:55 PM
#5
Yes, the pass cars would have used the 965 and 556 manifolds. They were sort of universal manifolds for any Chevy engine.
A single digit for the year on the casting date denotes that the engine came from Flint and 2 digits for the casting date denotes that the engine came from Tonawanda.
Corvette engines ONLY came from Flint.
A single digit for the year on the casting date denotes that the engine came from Flint and 2 digits for the casting date denotes that the engine came from Tonawanda.
Corvette engines ONLY came from Flint.
Ok, so my final question is about the corvette date codes, they do specify year right? I also read somewhere they may have not specified year on Vette ones, but passenger cars they actually ended in 57 or 58 etc.
the place acted like vette ones only had a month and day...
10-21-2018, 09:44 PM
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ALL CAST date codes that I've ever seen (blocks, heads, manifolds, water pumps, etc) have mo-dy-yr. Sometimes, some cast date codes can be difficult to interpret. I don't recall ever seeing a CAST date code that was just mo-dy. And I have seen several ex manifolds that do not have cast date codes. If a manifold does not have any kind of cast date code, then that pretty much eliminates the possibility of a question being asked.
10-30-2018, 12:10 PM
#7
Ok on to Heads now
The heads on our 58 (283) have the x58 on them, I understand the date code is under the valve covers and isn’t judged but was wondering about the way to tell when on the car (without removing valve covers to see the two digit date code)if they are Tonawanda heads or correct Flint Heads. Something about he casting symbols being smooth or rough I read somewhere on this forum. But Since I only have one set in front of me, can anyone explain better or get me a picture?
Last edited by Jason Conroy; 10-30-2018 at 12:12 PM.
10-30-2018, 08:51 PM
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The heads on our 58 (283) have the x58 on them, I understand the date code is under the valve covers and isn’t judged but was wondering about the way to tell when on the car (without removing valve covers to see the two digit date code)if they are Tonawanda heads or correct Flint Heads. Something about he casting symbols being smooth or rough I read somewhere on this forum. But Since I only have one set in front of me, can anyone explain better or get me a picture?
10-30-2018, 09:08 PM
#9
Wow thanks!
john, thanks that’s incredible exactly what I was hoping to see to make sense!