66 L 79 heat riser part #

[Matt Benson (46254)]

Can anyone tell me the part number for a '66 L79 Heat Riser - vin prod # 23814?

thanks,

Matt

[Joe Lucia (12484)]

Re: 66 L 79 heat riser part #

Matt------

As I recall (I'm out-of-town right now so I can't check my references to confirm my memory), the original part number was GM #3887024. That part was discontinued about 30 years ago and replaced by another number which I cannot recall. It's a 6 digit number beginning with "3", though. A GM dealer may be able to cross-reference from the above number.

[Larry Linder (22779)]

Re: 66 L 79 heat riser part #

I can tell you to be careful of the new repo - junk. The bolt circle is not concentric with the manifold. This causes the heat riser valve to hang up on the pipe. The repo valve has such a poor fit that the intake manifold may not get hot enough before the valve opens. The counter weigth sometimes comes loose too. I have seen some with loose butter fly plates. The holes may not be perfect either and if you torwque them up you take a risk of breaking the manifold. Always do a dry fit check. In one case I had to over bore the holes by 0.1 inches to make things fit.

You can spot the junk by looking at the bolt circle and the bevel on the bore.

When I look at this junk and I mean junk it makes me sick. There is a solution. If its not right keep sending it back for a full refund and insist on getting your shipping refunded - both ways. Maybe the suplier of this trash will go out of business.

I found a good used one, cleaned it up, put a new anit rattle spring on it and

[Matt Benson (46254)]

Re: 66 L 79 heat riser part #

What's your response to this item- junk or legit?

http://cgi.ebay.com/ebaymotors/Corvette-1957-74-2in-Exhaust-Heat-Riser-Valve_W0QQcmdZViewItemQQcategoryZ10076QQihZ002QQitemZ4586235099QQrdZ1QQsspagenameZWD1V

know of any issues with it fitting a 66 327-350?

thanks for your help!

-Matt

[Gerard Fuccillo (42179)]

Re: 66 L 79 heat riser part #

Matt,

Take a look at this post, on a 67 S/B

https://www.ncrs.org/forum/archive23.cgi?review=192215

I found that some of the generic or repro heat risers have a larger counterweight which forces one to mount the counterweight in the wrong direction. I recently OJed with some experts in Boston, and that was a deduct on most of the 67's we judged.

The outcome of my post above was that I refurbed my original, bought a repro a and took the spring off the repro and put it on my original.

Not sure about the ones on ebay, maybe someone will chime in. Maybe consider refurbing your original or one of them.

Jerry Fuccillo
#42179