Difference between 72 LT-1 & 74 L-82?
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Joined: May 2007
Posts: 96
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From: Burgaw North Carolina
Difference between 72 LT-1 & 74 L-82?
Hi to all! I love this forum, it’s packed with a lot of helpful information. Forgive me in advance if this question has been asked before, I was unable to find it in a search I did. My question is what is the performance difference between the 72 LT-1 and a 74 L-82? They both have 4.00x3.48 ins. 9:1 compression. With the 72 LT-1 putting out 255 net bhp @ 5600 rpm and the 74 L-82 putting out 250 net bhp @ 5200 rpm. I love the styling of both Vettes and personally own 74 convertible 4spd. This Vette has been in the family since 1975. Through the years I have read a lot about the LT-1’s and have often wondered what in the way of performance was so different between the two that creates such a buzz. I realize that 73 through 82 seem to be the red headed step child of the Vette family, and slowly those year models are starting to generate interest.
Last edited by Lights; May 29, 2007 at 02:03 PM.
Melting Slicks
Joined: Apr 2002
Posts: 2,337
Likes: 14
From: Norfolk VA
The 71 LT-1's gross HP rating was 330 due to the lowering of the compression ratio, which was 11.00:1 in 1970. The L-82 cam is the same as the L-46 cam of the 350-350 1970 engine. The LT-1 has a solid lifter cam which allows the engine to rev higher, transistorized ignition, and an manual transmission, with a Holley 770 cfm carb. (Someone will correct me about the carb) The 73 or 74 L-82 engine is the strongest of the L-82 family. Hope this helps.
Drifting
Joined: Jun 2003
Posts: 1,455
Likes: 5
From: Upstate South Carolina
There's a bigger performance difference between the 70 LT-1 and 72 LT-1 than between the 72 LT-1 and the 74 L-82. As you stated the 72 LT-1 was 255 net and the 74 L-82 was 250 net. The 70 LT-1 was 370 gross, probably around 300 net. The 71 was in between at 275 net (330 gross). The big difference was the LT-1's soild lifters. The 72 did not have transistor ignition. The 70 and 71 did.
Pro
Joined: Mar 2003
Posts: 742
Likes: 5
From: McMurray PA
Quick question: I never drove a 69-70 300 horse car. How much would it be lacking in seat of the pants feel versus the L46, assuming both were 4 speeds?
Drifting
Joined: Apr 2007
Posts: 1,892
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From: Springfield Illinois
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Racer
Joined: Feb 2007
Posts: 262
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From: FREDERICKSBURG VA
1971 & 1972 LT1's were pretty much identical, I owned one of each in the past. Properly tuned they would run 13.10's on 70's street (no grip) tires.
There was not as much difference in power from 70 to 71 as it looks on paper, the 9 to 1 LT1's just needed timing recurve & carb rejetting.
There was not as much difference in power from 70 to 71 as it looks on paper, the 9 to 1 LT1's just needed timing recurve & carb rejetting.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The difference between a 72 LT1 and the 74 L82 is huge. The motors are way different in the way they drive and perform. I would suggest a drive in both to see the difference. The 255 LT1 was way under rated. The LT1s had a high rise alum. intake and a 780 Holley with solid lifters and would be a high rpm motor. The L82, a good motor but a low rpm motor. It had cast iron intake and a Q jet and a much shorter duratio hyd cam. Both had forged bottom ends but they are quite different in the way they perform.
