Jump to content
Forums Gone... but not forgotten!
Pontiac of the Month

Ron Edelson's 1963 Bonneville

2023 May
of the Month

  • Welcome!

    Welcome to Forever Pontiac, where we keep the memory of Pontiac alive with great discussion, maintenance tips, restoration/modification progression "blogs" and help from professional & DIY mechanics. Also, wonderful competitions that occur regularly. Please register for an absolutely free account to join in!

Unmolested 1975 455

Recommended Posts


I am wondering if anyone has thoughts.  I have what I am "told" is bone stock 1975 455 (complete except for accessories....alternator/AC Pump, power steering).   I was also told that this was a running engine when pulled.  This engine has been sitting in my indoor storage for over 20 years.

The original idea was to swap out the 326 in my 1966 Lemans for this 455 but now, many years later I just don't know that I have the time or money to invest in this rebuild.  If I were to try and sell it, would I be better off parting it out or trying to sell the complete engine?  What would it be worth?  

If I decide to prioritize a rebuild, which would be a better candidate, the current 326 (old and tired) or the 455  (obviously we don't know what either engine looks like inside until it gets taken apart)...

Any thoughts are appreciated.


  • Like 2
Link to comment
Share on other sites

Tired of these Ads? Register Today!

Gravity72 - welcome to FP!

There are a couple of schools of thought here. You have to decide which camp you fall into.

Camp #1

My '66 Lemans is all original (including the stock 326 tired though it maybe). It will cost the same amount of money to rebuild the 326 as the 455. I can sell the 455 and use that money towards the rebuild of 326. I can add some performance goodies along the way to wake up the motor and still have a numbers matching car.


Camp #2

I want a hi-performance beast for my '66 Lemans. I don't care about having the original motor in my car. I am going to rebuild the 455 into a street beast, slap it in there and then burn rubber for days!


The bottom line is what you want to do with the car. Are you planning on keeping it or selling it? A numbers matching car (the engine, transmission, etc are what the car was built with from the factory) will typically be worth more than a car that isn't. A highly customized and detailed car can bring really good money, but a car that is mostly stock but isn't not numbers matching will be worth slightly less. Both engine have about the same amount of aftermarket support, with the 455 perhaps a touch more. The only Pontiac engines that don't get a ton of aftermarket support is the 301/265 and the 350 (pistons mainly).

The 326 and 455 are external dimensionally the same. Pontiac never had a big block/small block program. They changed the bore and the stroke. So most of the same hi-performance parts for a 455 will bolt into your 326. So you can stroke your motor, put in a more aggressive cam, put on better heads, intake, carb, add fuel injection, headers. etc. to wake up that 326. You can do the same thing to the 455, you will just have more displacement, HP, and torque.

  • Like 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Tired of these Ads? Purchase Enhanced Membership today to remove them!
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.