Thermoatat Housing to Air Cleaner Clearance

[William G.]

Greetings,

While not my first post I am rather new to the forum. My question relates to 1966 small blocks, but may be relevant to other C2s also.

I recently purchased a reproduction thermostat housing no. 3827369 from CC--although the source is probably irrevelant as it is a GM licensed item. My question is that there appears to be a lack of clearance between the top of the long screw (on the side of the housing closest to the hose)--ok bolt, but screw is a more proper term--and the underside of the air cleaner (the base).

Could someone with an original 3827369 measure the height of this housing from the intake to the top of the boss where the long screw attaches? My reproduction measures 2 5/16" in height to the top of the boss--but from the intake to the bottom of the air cleaner base is only 2 5/16" or maybe 2 11/32", which is not going to provide room for the head of the screw. I believe I have an original air cleaner base and the carb is a List 3367 (correct for '66 small blocks) and the intake is the original--date code and all. The screw head is positioned right beneath the edge of the air cleaner base and is a definite interference with the base

If original 3827369 housings measures 2 5/16" I must not have a GM air cleaner base. I suppose this boss could or should have been faced lower to provide the needed clearance. Help, please. Thanks.

Bill

[Stuart F.]

Re: Thermoatat Housing to Air Cleaner Clearance

Bill;

Right off the top; are you using an air horn gasket on the carb? Also, is it the base of the air cleaner, or just the snorkel that you are seeing a clearance problem? I also just read today that there was a spacer used to give clearance between the thermostat housing and the temperature sending unit. Do you have one of these?

Stu Fox

[William G.]

Re: Thermoatat Housing to Air Cleaner Clearance

Stuart,

Yes I have an air horn gasket..............but it wouldn't make much difference as I'm lacking the full height of the head of the screw--which is what, like 3/16"? And no, I don't have a spacer between the housing and the intake. I haven't tried to actually install the repro housing which I recently purchased but it measures 2 5/16" from the intake surface to the top of the boss in question and there is barely that much room between the top of the intake at the mounting surface and the underside of the air cleaner base. Maybe I need a big a.. crow bar to install the thermo. housing (all at once).

Bill

[John H.]

Re: Thermoatat Housing to Air Cleaner Clearance

I also just read today that there was a spacer used to give clearance between the thermostat housing and the temperature sending unit.

Stu -

The only '66 that used the thermostat spacer was the 427/390 with A.I.R.

[Joe L.]

Re: Thermoatat Housing to Air Cleaner Clearance

Bill;

Also, is it the base of the air cleaner, or just the snorkel that you are seeing a clearance problem?
Stu Fox

Stu------


Snorkel? No 1966 Corvette ever used an air cleaner with a snorkel. 1965 was the last use of a snorkel type air cleaner (on some small blocks) until snorkels (but much shorter) appeared again in later 1970 for some applications.

[Stuart F.]

Re: Thermoatat Housing to Air Cleaner Clearance

So hit me again fellows! Just trying to get things started here to help the man out. You all have any suggestions?

Stu Fox

[Ronald L.]

Re: Thermoatat Housing to Air Cleaner Clearance

This is what a 1966 327 air cleaner base - really - looks like.

One year only part and no repop out there...

https://www.forums.ncrs.org/showthre...+1966&uid=3848

click thread, can't repost the same picture twice

[William C.]

Re: Thermoatat Housing to Air Cleaner Clearance

I believe this has been discussed before, and the problem is you need a 660 thermostat housing on a '66 rather than the '369. The 660 uses a much lower angle of exit to the hose, and will cure the problem. I don't know it this was addressed in the newest '66 Judging Guide or not, but most of the '66 Mechanical judges are aware of it. It is called out in the '68 edition of the Chevy parts manual.

[William G.]

Re: Thermoatat Housing to Air Cleaner Clearance

Thanks for the responses..........but I'm really dumb founded (or is it just d...?). My air cleaner base certainly DOES look like original unmodified GM (course I guess it could be from, say, a '68 small block--but would the air horns be the same between a Holley and Rochester so that the later air cleaner would mount to the Holley?). I'm still hoping someone will measure their original 3827369 housing and report the dimension asked for (overall height from intake mounting surface to top of the taller mounting boss). IT COULD be that when the repro thermo. housing was machined the boss was not cut down enough to clear the a. c. base. MY 3827369 would require a minimum length for the cap screw (again, many people now call them bolts, but......) of 2 1/2 inches------so someone could measure the screw also. It is very easy to measure the housing, though, even if installed on the engine. Please, someone get me the measurement. Just the housing not to the top of screw (bolt?) head. I think those thermo. housings were used for sereral years and at least in 1966 were used on L79s and base 300 hp engines (the L79 housing was painted silver, though). Thanks again for the help.

Bill

[William G.]

Re: Thermoatat Housing to Air Cleaner Clearance

Mr Clupper,

Thanks for your response. I'm one revision behind on the judging guide and the 4th edition states that the correct housing is 3827369.......so, naturally that is what I bought from CC. And the '660 housing is aluminum, not iron. Right? Mystery solved.

Bill

[Stuart F.]

Re: Thermoatat Housing to Air Cleaner Clearance

Bill;

We having fun yet? Glad you have what appears to be a resolution yo your problem.

Stu Fox