1971 coupe with CGY engine

[Joe L.]

Re: Addendum

Steve-----

Well, this all checks out ok. Except for the tach (which could easily be changed) and the supply tank bracket (which is a lot more difficult to "obliterate" the vestiges of), the configuration you have would be consistent with a small block manual transmission car. However, we're still left with the date and coding problems on the engine. If the car left St. Louis with this engine, it would have to have been an off-line replacement.

One more thing that you might check is for the presence or absence of a 1/4" fuel return line adjoining the 3/8" fuel feed line. Base engine cars would have this and LT-1s would not. Sometimes, when "conversions" are done the line gets left behind. But, it's also very possible for someone to remove it.

[Steve Beech]

Re: Addendum

There is no return line. Was there a nipple on the tank where it terminated? I looked at the tank and there is no blocked off termination point.

Is the center crossmember which is welded in an indicator of the Higher HP than base 270 HP?

[Mike E.]

Re: Addendum

Welded-in crossmember means manual-shift transmission rather than automatic.

[Jim T.]

Re: Addendum

No Steve. Automatic cars had the bolted in crossmenber and the 4-speeds were welded.

[Steve Beech]

Re: Tank Sheet On Tank...Or MIA?

Chuck---no tank sheet that I can see. Unbolted the spare tire carrier and mirrored the top---don't see one nor a place where it was. Just dust and dirt.

[Chuck S.]

One Last Thing...

Steve, does your car still the emissions label on the driver-side upper firewall behind the brake mc/booster? If its there, what letter code is shown in the upper left-hand corner? Also, what condition is it in?...is it weathered with the edges curling up and cracked, or is it stuck down tight?

BTW, the tank sticker is normally located on the driver-side top of the tank, and is usually visible by depressing the rubber drain boot around the tank fill cap. I have heard of owners finding their tank sheets under "dust and dirt"; Unfortunately, in my experience, nothing visible but "dust and dirt" means the tank sheet is history.

[Steve Beech]

Re: One Last Thing...

The label is there---OK condition worn looking but stuck down-- the code is AX

[Chuck S.]

Re: One Last Thing...

Well...the emissions label sounds right too. Good reproductions are available, but I am pretty sure there are judges who can spot a repro label at several feet, just as there are qualified judges that can identify a high-quality restamp.

It seems unlikely to me that anyone setting out to "make" an LT1, and who knew all the details versus the base car, would not also know that CGY was a ZR1 suffix, and erroneously stamp the pad such that it didn't match the details of the car.

But, as Joe said before, the engine assembly date after the car build date is going to cost you some points in judging, but if the engine is genuine, the deduct shouldn't keep you from Top Flighting. Suggestion: Check the build dates on your carburetor, alternator, and starter. If these components have build dates that precede the A31 car build date by several weeks, this may begin to make some sense as a heavy repair at the factory as Joe suggested.

The heads are a problem. If you are right about the head cast dates being Feb 70, then I don't see how they can't be original (more deducts). You can't see the head casting dates with the valve covers installed, of course, but the casting symbols on the end of the heads will be significantly different between 70 and 71. Heads from 70 MY will have the double "camel humps"; 71 heads will have a symbol best described as a collection of rectangles with a truncated cone (See 70-72 TIM&JG, 3rd Ed, page 51).

[Chuck S.]

Correction:

A double negative slipped up and bit me. About your heads: "...then I don't see how they CAN be original...".