Chevy Big Block Casting number help.

[W117Monte]

Hey guys, i have a block here casting numbers on the back of the block...RR is k21 73
LR is 3999289. The deck numbers are gone. My chevy parts interchange manual says its a 454 from 70-79, and by the K21 73, im guessing it was made in 73. It is a four bolt, and it has the big pipe plugs on the filter housing. How can i tell more about this block. Is it a replacement block from GM? did they make a production 4 bolt in 73? thanks in advance.

[Furback]

I had crate LS7 and crate LS6 in the 70s, 4 bolt blocks with that casting number. Also, I have a 73 motor home 4 bolt block with this casting number. Actually, I threw away a CE 4 bolt block with this casting number, supposedly it was a Motion engine, the block had been froze and split the lifter galley all to shit. The heads off of this engine were stamped "Gioninni" or somthing like that. Rectangle port heads. It appeared to be a crate LS7 that had the heads prepared by "Gioninni". Tunnel with two 660 center squirters also.

[Furback]

I forgot to mention that this engine was in a Motion clone 70 Camaro black with white motion stripes. Was a Z28, Autumn gold, repainted black. So, the story goes that this car WENT to Motion for conversion. No proof. Car is still around, returned to original Z28.

[Furback]

I just saw a Camaro race car in the photos with the name of the head guy. GIANINO. Thats the name that was stamped into the heads.

[Igosplut]

I have a CE 427-425HP that's a 289 cast (72 date code)

[W117Monte]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Igosplut</div><div class="ubbcode-body">I have a CE 427-425HP that's a 289 cast (72 date code) </div></div>

Funny you should say that, because we got this block as a complete engine. Thinking it was a 427-425 horse. the intake and heads were both dated 67 or 68( i cant remember which) and i sold the heads on Ebay for pretty good money. They were rect port heads. This block was in my dads race car as a 454 up until recently and he swears the machine shop had to notch the block for the 454 crank. Also it was still stock bore. I suppose if you could get a 427 crate, you could also get a shortblock? maybe that would explain the heads.

[RichSchmidt]

The 289 casting is basically the successor to the 512 block. It is a thick wall casting,and was available in 2 or 4 bolt. I had one in my race car with 2 bolt mains and studs .060&quot; over making just a tick over 600hp@7300rpm on motor and a little under 1000 hp on a 350 shot of nitrous. The block held up fine,and it eventually threw a pair of Manley rods out the side after about 700 runs,about 100 of which were on nitrous. The 289 block was used in trucks,vettes and hi-poi cover the counter engines.