Rats and Mice

Print Friendly, PDF & Email

What’s the difference between a mouse – and a rat? If you know cars, you know the answer. If not, here it is – in case you might be interested:

A mouse is the name affectionately bestowed by people who love cars – and specifically, those made once-upon-a-time by Chevy – upon the small-block series of V8 engines that made their debut in 1955 and could be found under the hoods of various Chevys for decades thereafter. They ranged in displacement from 265 cubic inches through the more famous 327s and 350s that powered Camaros and Corvettes and Novas through the ’70s and into the ’80s.

We used to refer to engines this way – rather than the metric way. Which is to say, the European way. The American way used to be different – and that was good because everything wasn’t the same.

Cubic inches of displacement also has better mouth feel – more emotional resonance – than anodyne liters. The latter being the same, irrespective of brand – if the size is. A 2.0 liter four under the hood of a VW vs. a Subaru vs. a Ford. It all sounds the same. And it makes you want to yawn. It certainly doesn’t inspire you to talk about it, except insofar as maybe ordering a part for it.

But it’s different – was different – when you had a 283 or 327 under the hood. Especially when it was a Power Pack, or a Fuelie. In part because those latter had emotional resonance and because no one else had them. Only Chevys had 283 Power Packs and 327 Fuelies – both denoted by the cross-flagged emblems that made you proud to show off what you had under the hood.

2.0 liter fours are covered by black plastic – because no one cares what’s under them.

And, of course, no one refers to them by affectionate names like mouse – or rat.  The latter referring to the family of big block Chevy V8s that came in sizes ranging from 409 to 454 cubic inches – and that had the cross-flagged emblems, too. A rat could be distinguished from a mouse at a glance, by dint of the obvious difference in physical size. A rat had valve covers that looked twice as wide as those of a mouse – and most rats were painted a bright red color while the mouse was usually dressed in orange.

Speaking of which:

Colors also used to differentiate one brand’s engines from another’s. Ford small blocks, for instance, were usually painted a dark blue color. Pontiac V8s were painted a lighter, almost pastel blue – as well as a magnificent light blue-green metallic, earlier on. Some of the very last of them were painted a deep blue metallic color that was similar to the color AMC – if you remember AMC – used on its V8s. Which had oddball displacements such as 304 and 401. Both of which made you feel something when you said them.

Oldsmobile Rockets were golden – literally. And (like Pontiacs) they didn’t come in big or small blocks but did come in displacements ranging from 260-something all the way to 455s. But they were entirely different engines, even if they touted the same displacement.

Hemi Orange was the factory hue of the Elephant – the name affectionately given to the 426 cubic inch Hemi of the ’60s and early ’70s.

The mighty Elephant made one horsepower for every cubic inch of displacement and came standard with dual quads – or two four barrel carburetors.

This was another difference that made one.

Some Chevy big blocks had three carburetors – and so did some Pontiac V8s. Some – a very few! – Chevy small blocks, as in the case of the original 1967-’69 Camaro Z28 – could be had with two four barrels mounted diagonally across from each other. This was the memorable cross-ram version of the 302 small block.

Today, of course – and for the past several decades, in fact – all cars, irrespective of brand, have been fed fuel the same way, via electronically controlled fuel injection. The system has many merits – but personality isn’t among them. Many of them use the same parts made by the same company (Bosch) and while they work very well and very reliably, the same can be said of most refrigerators, too.

New cars are “connected” – but it’s hard to connect with them, because there’s not very much to connect to, on a human level. They are like dress store mannequins in that one is pretty much like the others.

Unlike, say, a ’57 Bel Air with a fuelie small block under the hood. Or even a ’76 Pontiac Trans-Am such as the one owned for the past 30-plus years by the writer of these words, who drives something new – and anodyne – every week but repairs to the garage and goes for a drive when he needs to connect with something real, that was different, that makes him feel something other than bored.

It’s impossible to feel that when there’s a shaker scoop poking through the hood – and a 455 Indian underneath it.

. . .

If you like what you’ve found here please consider supporting EPautos. 

We depend on you to keep the wheels turning! 

Our donate button is here.

 If you prefer not to use PayPal, our mailing address is:

721 Hummingbird Lane SE
Copper Hill, VA 24079

PS: Get an EPautos magnet or sticker or coaster in return for a $20 or more one-time donation or a $10 or more monthly recurring donation. (Please be sure to tell us you want a magnet or sticker or coaster – and also, provide an address, so we know where to mail the thing!)

My eBook about car buying (new and used) is also available for your favorite price – free! Click here.  If that fails, email me at EPeters952@yahoo.com and I will send you a copy directly!



  1. Oldsmobile had small-block and big-block engines as well. I’m not as well-versed in the 1st-generation engines (from 1948 to sometime in the ’60s) as in the 2nd-generation engines (from sometime in the ’60s to 1990), so this will reflect that, but IIRC the big-block displacements were 400, 425, and 455 cid, while the small-block displacements were 260, 307, 350, and 403. Big-block engines went away after 1976, replaced by the small-block 403 that only stuck around until maybe 1979 or 1980. (403 cubic inches in a small block required squeezing cylinder jackets so close together that there was no coolant flowing between cylinders. They can’t be bored out as much as other engines without running into cooling issues.)

    Note that this only applies to gas engines. The diesels were a different beast altogether, with the 350 diesel being closer in some dimensions to big-block gas engines. (Contrary to popular misconception, Olds diesels weren’t merely gas engines converted to run on diesel fuel, but were larger, stronger blocks to take the added pressure. For a while, racers were converting diesel engines to gas to get more bulletproof gas engines.)

  2. Eric: or rat. The latter referring to the family of big block Chevy V8s that came in sizes ranging from 409 to 454 cubic inches.

    Not to be picky but the Rat motors started at 396 CI and isn’t the 409 classified as a “W” motor along with the 348? And yeah I’ve got a rat motored Chevy sitting in the garage.

  3. First new car I ever bought was a 1977 AMC Gremlin. One of the ugliest cars ever. The price got me. 3K, $70.00 per month payment for I think 3 years. Drove that car all through grad school, 4 years I was not smart, had to work. Until I wrecked it after grad school. Totally my fault. Totaled the car. But boy I had a lot of good times in that car. Drove across the country 7 times. East coast to west coast. plus a few North/South trips to various places. I think it had a 6 cylinder engine. I did replace the entire radio and stereo the day I got it. Put in a cassette player with Dolby. Yes that long ago. Saw the Redwoods in California, the Rockies, Wall Drug, all kinds of places of interest.

  4. Off topic: The Aspen Ideas Fesival (summer Davos) attendee list has been posted, and look who’s right at the top:

    Among those attending:

    Mary Barra, Chair and CEO, General Motors

    There you go, Eric. Your chance to rub elbows with the most impor’an’ woman in the industry. I’ll let you crash on my couch, only an hour and a half away. Tickets are on sale now, “only” $5000 for old timers, $4,000 for those under 40. I guess that’s reaching out to the millennials and Gen-Z kids. No word if there’s a DE&I discount.

    Of course if you’re feeling generous there’s the Patron Pass. The reduced price for 2023 is $13,000. Best value


    • Morning, RK –

      I could not endure being within the airspace of that wench. She and those like her are guilty of nailing the coffin of the car industry shut. They are turning cars into homogenous, disposable appliances – without realizing (or caring) that there is an inherently limited market for different brands of toasters.

      May the ghost of John DeLorean drag her behind a ’66 GTO.

  5. Dodge went to “392” CID for the SRT Hemi. Even the badges say it.

    Although I was once their biggest fans, I am not a fan of Stellantis (since they insist on a ludicrous amount of complexity, which negatively impacts both quality and cost), I do give them credit for introducing the Demon.

    Why do I say this about complexity? Because they have some center stacks with 34 PNs – and they’re all the same color. They actually plan to have some PNs have a 0.2% take rate.

    The center stack is the module that has your HVAC and audio and option switches.

    Steering wheels? Like 60 PNs in some cases.

    Somehow the JOEMs manage to sell a lot of cars with like – 3 center stack P/Ns.

    However, I can think of no larger middle finger to the “ban all gas engines NOW!!!” crowd than the Dodge Demon.

    I give them much credit for that.

    Hey Eric: When is Dodge getting you one of these to test? That might be a fun car.

  6. I had a one of those 283s in a 1966 C20 – best V-8 ever – bullet proof. The big mistake of boring out the cylinder out until there is no space between cylinders and you get a blown head gasket. The older engines, with lower displacement last longer IMO.

    Another impressive engine was the 318 wide block, I have it in a 1965 Power Wagon W200 – which still runs perfect 58 years later, and will still be running perfect when every Tesla ever made is crushed. And I will be glad to flatten Teslas with it. I think I cut over 200 cord of wood with it, plowed snow, has a separate transfer case (with PTO) and no aluminum anywhere. Solid Detroit iron – but pales in comparison to the previous WM300 model built after the war.


    You can still get any part: https://www.vintagepowerwagons.com/

    How many trucks nowadays have a PTO winch? Not a one, thus all modern trucks are just junk. And what fool would dare take a modern expensive as hell truck into the woods? They are all show.

    When I used to live in McCall Idaho I cut firewood and would come into town fully loaded with a cord and a half with a couple of Stihl 066s saws stuck into the wood on top, chains dangling on the sides, handyman jack bolted to the custom flat bed with tall sides. I would be all covered in sawdust and oil. Out of towners would be scared shitless. LOL I was sure glad I was not them – flatland city dwellers.

    • So many sneered at the “Canadian” or “Poly” 318, but that was Mopar’s “bread and butter” engine from 1957 to 1966 (1967 for Soviet Canuckistan). Went into all but the “A-bodies” as the base V8, with a Stromberg 2-barrel carb, solid tappets, and ran on regular grades of gasoline. Canada had, until 1965, a 313 cube version of the same engine (slightly smaller bore, IDK why). This plant had “character”! You learned the fine art of adjusting the valves “hot and running” (same maintenance on Mopar Slant Sixes until 1977) and a kid could learn to rebuild that Syromberg in auto shop.

  7. In the 60s Mopar also offered a V8 with 3 two barrel carbs. Put it in some dodge darts, called “super bee six pack”. Don’t remember the displacement.

    • 440 cubic inches. Adding 3 individual two-barrel Holley carbs on an aluminum intake manifold, some stronger connecting rods, and a hotter camshaft (among other things), turned it into a “Six-Pack” from Dodge (Super Bee) or a “6-BBL” from Plymouth (Road Runner) – 1969 A12 code cars…insanely valuable today! Also installed in 1970 & ’71 B & E body cars from both.
      In my opinion, better than a Hemi of that vintage. And WAY better than a 2.0 four cylinder!

        • Yes friend had the Challenger 340 Six Pak, I was lucky to drive it several times. If I remember the throttle was a bit stiff probably good thing since it was gobs of power ready to let loose.

          So many cars we wish were around today! I chime in with many nostalgia car stories so from that you can see how available these great fun rides were to middle class ‘60s and early ‘70s America.

  8. Gosh, articles like this make me wax nostalgic…and mourn for what we have lost just in my lifetime- not to mention my parent’s lifetime….. But keeping these memories alive is SO valuable, and we are the last generation to have experienced that world.

  9. As a young buck, my Vega station wagon (aka the raped ape) had a 140 cubic inch inline 4 that produced 90 hell raisin’ horse power. Why do I still remember that?

    No idea what 140 in^3 converts to into metric & don’t care enough to find a formula to do so.

    • One liter = 61 cubic inches

      So the Vega engine was 2.3 liters.

      Saw a Cosworth twin-cam Vega in the Home Depot parking lot last week — a 2-liter rated at 110 hp. Only 3,508 were built.

      • 7 x 61 = 427 cubic inches, 7000 cc engine. Actually, 427.1662 cubic inches, rounded off to 427 cubic inches, 6999.99 cubic centimeters.

        7 and 61 are prime numbers. Doesn’t mean anything, but they’re there anyhow.

  10. ‘No one refers to [2-liter fours] by affectionate names like mouse – or rat.’ — eric

    What about an EeeVee motor: nothing but a silver can concealed in the undercarriage?

    It has no analogue in the animal kingdom, though the drive train of a Tesla Model S somewhat resembles a bacterium at 1,000 X magnification.

    Got penicillin?

  11. The Commanders ‘71 Nova had a Chevy 307, what a great motor. Early no lead heads were beefy. That Nova would smoke my 350 ‘70 Firebird, as she stop light drag raced me on Hwy 99 south of Seattle. Poor Firebird was a smogged out California car.

    Also lost in Before Time the “sleeper”. Buddies mom had a early ‘60s Impala four door, white, button hubcaps. She said “look under the hood”. The mighty 409! She got a hoot out of shaming youngsters in their home built hopped up muscle cars, left many in her dust.

  12. Displacement carried beyond the muscle car as well. Remember the fantastic Cadillac 550 cubic inch monster? Just the thing to dust your country club friend with his mere 413 cu in Imperial. And touting the engine sized worked great in reverse for Rolls Royce, which famously only said it was “adequate” and the top speed was “as fast as you wish, sir” as if a Rolls driver was above the fray.

    Unfortunately unique engines across divisions went the way of 60% market share. Now that everyone’s using a 2.0L (thanks to EU regulations) there’s not much point in building your own. Might as well just get to work integrating whatever is coming out of China and be done with it.

    • The big Cadillac V8 was a 500 CID V8. I know as I had a 1976 Cadillac Coupe de Ville as my first car. Big Ol’ American boats were cheap in the 1980s and 90s as nobody wanted a beast that could barely get 9-10 MPG in stop and go traffic.

      Originally when it came out in 1970 it boasted 400 HP (Gross rating) but by 1976 emissions strangled it down to 180-190 depending on what source you check.

      I do recall a funny story: I worked in a quick lube/quick tune place for a couple of summers in college. The Caddy was my daily driver. One of my coworkers wanted to see what a 500 CID V8 looked like. I took him over to my car and opened its hood.

      He wasn’t impressed. I think he expected it to look like a 426 Hemi with big chrome valve covers and spark plugs in the middle of the cover. It was just a big blue V8 with no chrome or anything else. It could’ve been a Chevrolet 350 for what it looked like. 😆

    • I know the feeling: My 1968 Olds Delta 88’s Rocket 455 was fire engine red: the better to distinguish it from the 400 and 350 cubic inch Rockets, which were painted bronze and gold, respectively.

      Around 1970, Olds went to a medium metallic blue for its 455s,and later took on the generic GM Corporate Blue, and the last “true” Olds engines, the 307s, were basic black.

      And then the Olds Rocket went away altogether…and so did Oldsmobile.


Please enter your comment!
Please enter your name here