BB GM Heat Riser # 3940977

[GaryC]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: John Brown</div><div class="ubbcode-body">Here is a picture of one that has the number 3746844 cast into the outside of the weight.



This is donut side up. </div></div>


I'm re-opening this thread, I have 2 of these heat riser valves and have no idea what they go to. They both have 3746844 cast into the side of the lever block. Anybody ever figure out what these are supposed to go on?

[John Brown]

I'd like to know too, then I could dust it off and sell it. [img]<<GRAEMLIN_URL>>/naughty.gif[/img]


Luckily it don't eat much.

[John Brown]

Since this was brought up again I did some research on the valve with number 3746844 on the weight. It seems that the 844 number is just an I.D. for the weight and is not related to what the valve fits. The same weight is used on some 2 1/2&quot; big block valves and some 2&quot; small block valves. Back to the drawing board on this one. I think maybe I'll just put my 2 1/2&quot; valve on ebay with an accurate description and send it to a new home.

[68z28kk]

The 977 number supercedes 3887033 which fit '65 to '68 Camaro Chevy and Chevelle. The '69 396 Camaro used the 3940977 valve which was replaced by the 3969903 by June of '70. This came from the GMPartswiki website. Clint

Originally Posted by travlnz28

Ed,

Did your part number supercede another number? I can't find your number in my GM books. I have a GM heat riser but it has another number stamped on it.

[GaryC]

Did the BB use the 2&quot; and the 2 1/2&quot;? OR is it 2&quot; for small block and 2 1/2&quot; for big block?

[John Brown]

2&quot; small block

2 1/2&quot; big block plus 300 horse and up 327's and many 348's and I believe all 409's

[GaryC]

In case anyone needs to know this info, I just happen to look in my 1969 Impala A.I.M. and found the part number for the heat riser John Brown posted a pic of and is the same as what I have 2 of... Part #3887024. I Googled the number and found this ebay link...

http://www.ebay.com/itm/NOS-GM-3887024-H...#ht_3282wt_1007


and this link that indicates what that part number was used on...HR024.


http://www.hamiltonmanufacturing.ca/hrv.htm

I hope this helps everyone out. If anyone has a used 3887023 I have the 2 3887024 I'll trade you.

[John Brown]

Gary, the 3887024 valve on ebay is mainly for a small block. Look down further at the applications he shows from GM parts books. No doubt it's for a 2&quot; exhaust system. The one I posted pictures of is a 2 1/2&quot; valve for a big block. As I posted above, the 3746844 number on the weight is generic, same as the ebay seller says. It was used on both big block and small block valves.