While perusing my local classifieds today, I came across an ad of someone selling a 318 race engine. Mind you, I have no specs for this engine, but the guy showed a page from a book, listing casting numbers for Mopar engines. Next to the casting number, it listed the engine size and years produced, however, next to this casting number it just said 318 LA race engine.
4104320 LA race engine.
I could not tell from the picture what book this was from. Can anyone shed some light on this, is it some special block?
Thanks.

There is a 4104230 318 block casting from 1980 - 1983. (Dxylexia on the 23/32?) OEM 318's were also available with a Thermoquad, then Quadrajet 4 barrel starting in the late '70's and/or early '80's, but there was nothing "race" about it.

Does the photo show it OEM or built with aftermarktet stuff?

The X-block may have had that casting number also. Slight chance the block could have been been built. I'm not familiar with the external differences to look for between an OEM 318 block and a factory race block. "X" perhaps? Do more research....I'm a bit fuzzy.

Just look for the big X behind where the alt. would be.

But its more of a common mistake then you think with the same block casting people "thinking" they really have an race "x" block.

And the X never had the dipstick hole drilled, not many racers did it either.

On a side note: Back when we ran in the dirt track hobby car class, we were always points racing. There were generally 30-40 cars in our class through out a year. The end of the season points paid pretty good money, but only to the top 10 in the standings. With us always being always broke, that point money often helped us get set up for another year. For 14 of the 15 years we ran that class, our little poorly funded Mopar managed to finish in the top 10 in point standings. One reason we were able to do so was because we never missed a week. Generally, our motor of choice was a 383 or 400, but there were times we simply didn't have a reliable 383 or 400. We did have a backup 318 motor & trans though. The 318 had 340/360 heads, a non stock cam, a good carb and a good dist. Though well under the power our big blocks, the 318 did pretty well in the well handling car.

Most of the guys we were running with knew when we were running the 318 (it sounded different), but most couldn't tell we were down on power because of the way we finished, not much off our normal pace. At some point in time, someone recognized we had a small block on the days it sounded different and questioned me. I told him we had our special race 318 in the car. I told him it was a factory specialty race motor and we didn't run it often because it was so valuable, far too valuable to destroy in a hobby class car. Most of the Chevy and Ford guys had no idea what kind of "special" motors Chrysler built, so many accepted my word. The ones that knew, would smile and go along. It was just part of the fun back then.

So, I'm hearing about this race 318, and I'm wondering if someone has our old backup motor...

My one buddy always had Mopar motors. To him, any thing with a factory 4 bbl carb was a "police Pursuit" motor. He was thrilled one time to find a mid 80s Diplomat with a 318 Police Pursuit motor in it.

Gotta watch those 318s, you never know when a Race Special version will show up. Gene

I tend to be a bit dyslexic at 3 am. It is a 4104230 casting number. I am going on pictures posted in the ad. One picture shows a page with casting numbers and sure enough, it says 318 race engine next to the casting number. I don't know if the guy found a website that's blowing smoke up his patoot or what. I just found it interesting and curious. Maybe I should buy it and see if it's faster than my other 318 that has a factory 4bbl intake on it!

Didn't some of the factory R series blocks come with a 318 bore size? 3.910 wasn't it. Maybe that is what the OP is referring to?

I think so myself, but no part numbers to back that up.

R3 blocks where availabe with a 3.91" roughbore.
But sitll not a factory 318 race engine.

This is the page that the seller shows in the ad. Researching this I found that someone on forabodiesonly, ran across one of these engines last year. The consensus was that these blocks, while having the same outer dimensions, were cast with thicker webbing inside, more metal around the bores and 4 bolt mains. I can neither confirm or deny this information.

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Mopar Engine Casting Numbers

Here is a list of Mopar Engine Casting Numbers. They cover a wide range of engines including the popular 318, 340, 383, 400, 413, 426, and 440 engines. You can find your casting number on the left hand side of your engine. Don’t get this confused with the partial VIN number that is also stamped in your engine which is on the right hand side of your engine. Hopefully you will find this list helpful.
CASTING NUMBER SIZE FAMILY YEARS OTHER COMMENTS
1737629 361 1961 - 1964
1851629 413 RB 1961
1852029 413 RB 1962
1852029 413 RB 1962-63
1852029 426 RB 1962-65
2120229 361 B
2120329 383 RB 1959-60
2120429 361 B
2120529 413 RB 1959-65
2128854 361 or 383 B 1964
2202843 170 G
2202857 225 RG
2205528 225 RG
2205630 170 G
2205697 413 or 426 RB 1959-65
2205712 361 B 1958-66
2264230 318 A 1960-67
2264478 170 G
2406730 426 RB 1963-65
2440873 426 RB
2463230 170 G 1965
2463252 273 LA
2463430 225 RG 1966
2465330 273 LA 1964-66
2466090 318 LA
2468030 413 or 426 RB
2468130 383 B 1959-71
2468230 318 A
2468330 426 RB 1964-65
2468330 426 RB 1966-71 HEMI
2532130 383 B 1965
2532230 426 RB 1964-66 Wedge
2532630 318 A
2536030 318 LA 1967-75
2536130 273 LA 1965
2536430 440 RB 1966-72
2566080 318 LA
2586430 ??? ?? ???? Contact Us If You Have Info
2658836 426 RB
2658930 361 B 1965
2780930 340 LA 1968-73 Not T/A or AAR
2806030 273 LA 1966-69
2806030 318 LA 1961-74
2806130 273 LA 1965-69
2806830 225 RG
2899830 383 B 1970
3418496 360 LA 1971-74
3577130TA 340 TA LA 1970-71 T/A and AAR
3614230 400 B 1971-72
3698630 400 B 1973-78
3698830 440 RB 1972-78
3810230 360 LA 1975-78
4006530 400 B 1976-78
4006630 440 RB 1975-78
4104230 318 LA Race Engine
4179930 360 LA

Wasn't there a 318CI engine built for Indy car racing in the 70's?

Must be the optional engine if you didn't want the base 383 Hemi.

Weslake 318

I remember that short lived experiment. Wonder what the thinking was on Weslake not leaning the intake banks over, injector position took priority over air flow path?

Mt. Harms found one of those blocks on CL a few years back IIRC.

Very interesting article, however as related to this thread:

"Based off of a production 318 LA series small block"

No 318 race block here...

Theoretically a race block could be said to be based off the stock block as well, just you know, beefed up in the spots the stock block is weak.

If you look at the evolution of stock blocks improvements are made all the time and they are generally based on the original design, but improved.