1972 LT-1 Engine Stamp Pad

[Wolf S.]

hi all,

I've recently come across a 1972 LT-1 T-Top (build date May 9) with an engine stamp pad suffix CRT.

In the 70-72 technical/judging manual(4th ed.) on page 55, it is written quote "Chevrolet servie records list CRT, CPH and CPJ codes, but Flint and Tonawanda report none were produced. Their existence is unverified."

Any ideas? Is this a special engine?

[Kevin G.]

Re: 1972 LT-1 Engine Stamp Pad

Wolf,
This info does not answer your question but my LT-1 has a build date of May 10, 1972 and has a VO327CKY stamp. You might be onto something neat!

[James G.]

Re: 1972 LT-1 Engine Stamp Pad

vin 20854 was built around May 9, 1972 so your April 19 assembly date fits the mold. And yes, CRT is a valid LT-1 code, but with A.I.R Smog pump. The CKY was the same engine, but no smog A.I.R system. I will bet your car was sold new in California because of the smog pump system.

[Kevin G.]

Re: 1972 LT-1 Engine Stamp Pad

vin 20854 was built around May 9, 1972 so your April 19 assembly date fits the mold. And yes, CRT is a valid LT-1 code, but with A.I.R Smog pump. The CKY was the same engine, but no smog A.I.R system. I will bet your car was sold new in California because of the smog pump system.

My CKY has the AIR.........?

[James G.]

Re: 1972 LT-1 Engine Stamp Pad

My CKY has the AIR.........?

Al Colvin's "Chevy by the Numbers" says CKY has "NO" Air Induction Reactor smog pump system. Again, if the GM "UNION" assembled the car, anything is possible.

[Kevin G.]

Re: 1972 LT-1 Engine Stamp Pad

Mr. Colvin's information is apparently incorrect.

[Michael W.]

Re: 1972 LT-1 Engine Stamp Pad

I believe that all LT-1s had AIR irrespective of destination.

[William H.]

Re: 1972 LT-1 Engine Stamp Pad

Clicky http://corvette-world.com/corvette_1...tion_codes.php

[Wolf S.]

Re: 1972 LT-1 Engine Stamp Pad

would be interesting to note how many on the board have a crt suffixed engine.

[Paul O.]

Re: 1972 LT-1 Engine Stamp Pad

Just to chime in all LT-1 no matter what state they were delivered to had the A.I.R. system installed. California cars may of had some additional or parts changes per there clean air requirements but the A.I.R. system already on board.

Paul 18046

[Duke W.]

Re: 1972 LT-1 Engine Stamp Pad

California had NOx tailpipe maximums beginning in 1971, but there was no NOx standard for 49-state cars until 1973.

AIR was a HC/CO control system, which had nothing to do with NOx.

Engines didn't require EGR to meet this early CA NOx standard until, but may have different spark advance map calibration. The LT-1 cam has enough overlap that it probably met the CA NOx standard without any additional work, but it would still probably have required a different engine code just for administrative/legal purposes.

Duke

[Mike G.]

Re: 1972 LT-1 Engine Stamp Pad

my 72 lt1 is an april car and it is a cky. it also has AIR. i have never seen an lt-1 that did not have AIR. california car did have AIR and it has some other stuff as well. california car has a large metal plate under the carb. sticks out about 2" all the way around. also has two emissions lables.

[Mike G.]

Re: 1972 LT-1 Engine Stamp Pad

did you buy this car yet?

[Billy O.]

Re: 1972 LT-1 Engine Stamp Pad

hi all,

I've recently come across a 1972 LT-1 T-Top (build date May 9) with an engine stamp pad suffix CRT.

In the 70-72 technical/judging manual(4th ed.) on page 55, it is written quote "Chevrolet servie records list CRT, CPH and CPJ codes, but Flint and Tonawanda report none were produced. Their existence is unverified."

Any ideas? Is this a special engine?

Wolf,

I've commented a few times on the CRT code (some of this should be in the archives). It would be interesting to see if your car came from CA. I believe mine did. I've seen no conclusive information on the CRT code with the research (minimal) I've done or the correspondence with Terry M. and Sal C. Let us know if you find anything out.

Billy

[Terry M.]

Re: 1972 LT-1 Engine Stamp Pad

There is a wide range between the VINs on those two cars. That is the most interesting feature to me. If there are two, there are lots more.

Something put on at Flint engine is different between the CRT and the CKY. The real challenge for all of us will be to figure out what that is. Flint didn't assign a different suffix code without some difference in the engine assemblies they shipped. You guys who own CRT engines might want to take the effort to find out where you car was originally delivered -- that might provide a clue to the why, but we still need to identify what drove the different suffix code.

For 1972 the base Corvette for California (CDH & CDJ) in addition to AIR equipment had a paper sticker affixed to the windshield stating compliance with California clean air regulations. Those engines had the brackets and exhaust manifolds compatible with AIR installed at Flint -- thus the different suffix codes. I haven't looked, but they may have received different distributors than 48 state base engines as well. Those are the kinds of features that brought about different suffix codes.