1972 SS-396 LS 3

Discussion in 'Original Drivetrain Topic' started by GREGS396, Nov 24, 2017.

  1. GREGS396

    GREGS396 Veteran Member

    Oct 16, 1999
    allentown pa
    I have been restoring a 72 SS-396 that I purchased nearly 15 years ago. I want to get some information and feedback from any other members who may have one, or may have owned one at some point. As we know, the LS3 dropped in the HP ratings for 72 in comparison to 71. I know that the 71 version was rated at 300, and I believe that for 72 it fell down to 245 or so. Here's where my car gets a bit interesting. It's an early build 72, 10A to be exact. I have every bit of original paperwork for the car since it was new, including the window sticker. The window sticker clearly lists the engine as an LS3, 300hp. The engine itself did come with the factory chrome valve covers along with the chrome air cleaner lid and the 300 HP sticker. I know that at some point during the year that the chrome air cleaner lid and valve covers went away. I've seen a few other members cars that still had the chrome valve covers without the air cleaner, as well as some that didn't have either. I don't know the build dates of those others, so I can't make any assessments as to when any changes took place. Just looking to see if anyone else has an early build car like me, or if anyone is familiar with any other carry over engines from one year into the start of the next. I have a few more questions on the car after this gets going....
  2. Ricks72Z28

    Ricks72Z28 Veteran Member Lifetime Gold Member

    Jan 1, 2005
    The engines were the same internally and it was just the way they stated the HP ...Gross vs Net... Whats the build date of the engine on the VIN pad?
  3. GREGS396

    GREGS396 Veteran Member

    Oct 16, 1999
    allentown pa
    It's 0924, I knew about the HP rating just not sure when it changed. My 72Z is a 12A car, and has the lower HP rating of 255 vs the 330 from 71.
  4. 70 SS/L78

    70 SS/L78 Veteran Member Lifetime Gold Member

    May 5, 2005
    Rockford, MN
    Hi Greg,
    I always wondered what happened to your car and if you ever finished it. Good to hear you still have it.
    Like Rick said, the horsepower rating was just a numbers game on paper, no actual difference in HP between 71 & 72.

    The last 1972 396 car I owned was considered a very late build, 03D, due to the strike ending production after the 1st week of April. It was a very original car and had a chrome air cleaner lid. I believe the lid was original as it had the correct dimples for the wing nut. There were no signs of any decals on the lid. I don't believe there was ever a 240 HP or whatever sticker made for the LS3 air cleaners in 1972. So I'm guessing they may of used up the remaining 300 HP lids from 1971? Or maybe the switch took place in January of 1972?
    Also, It did not have chrome valve covers.
    Last edited: Nov 25, 2017
  5. PaulC

    PaulC Member

    Mar 22, 2001
    I have a '71 SS/RS LS-3 that I bought from the original owner over 30 years ago. It had aftermarket carb, air cleaner and valvecovers, so I have no idea what was originally installed. I was supposed to get those original parts with the car, but didn't. I have since located a air cleaner assembly. The 396 was actually 402 cubic inches as Chevy punched the 396s .030 starting in 1970 and was rated at 300 HP with 8.5 to 1 compression. It had oval port open chamber "smog" heads which look to have larger chambers than their big brother rectangular port open chamber heads. In 1972 GM changed to a NET HP rating which I believe was 240 HP, else the engines were identical to 71.

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