74, you reversed your gidits.
400
72 - 80, 2 bolt mains

 

330817 casting was used 1970-1980. The T0404TLM is Tonawanda plant, April 04 and the TLM suffix was used on late 70s truck applications.

 

Looking at the dished pistons it is something after unleaded gas came to be. I think that was about 1971. That forth, and fifth photo showing the numbers embossed on the back of the casting.... Go to Jegs website, they have a listing of engine block numbers, and what they left the factory as/ yr It's not in the parts section but maybe the help section. how to videos stuff like that. The chart is down at the bottom of one of the articles/videos.

Plainly it is a SBC. Where is the rest of it? Heads have numbers cast into them too.

 

Yes, it's a 400.

Last 3 digits of the casting number, ending in "817" confirm that.

There were only 3 different casting numbers used for the 400... last three digits are "509", "511", "817".
The 509 and 817 are always 2-bolt main, the 511 is 95% of the time 4-bolt main but there are some 2 bolt.

Really doesn't matter what the head casting number is....all 400 heads are smog castings....junk basically.

 

The color indicates it’s a Ford???

Bogie

 

Blue was between orange and the new black.

Around 1977 to early 80's.

 

It's a 400 SBC, but from the era known to not have great metallurgy. Does it have 4 bolt mains or 2 bolt mains? The 2 bolt main blocks supposedly had thicker webs than 4 bolt had.

 

The "817" block casting is always 2 bolt from the factory.
The "509" block is the same way, always 2-bolt.

The only 4-bolt 400's were 1970-72 with the "511" casting number.

 

The pistons are the worst imaginable with no quench. Knock knock knock written all over them lol.

 

A little more 400 info I'll add.

2-bolt or 4-bolt, webs are the same ....the difference is the factory straight outer bolts on the 4-bolt are in a spot that weakens the block because of the material lost to the bolt hole in that location, it weakens the web.

This is the reason the aftermarket splayed caps help, as they angle the outers bolts into a thicker section of the casting that is tied to the crankcase outer wall and the floor of the water jacket.

I've had both a "509" and a "817" machined here last fall, the 817 was noticeably heavier to every one who lifted it, commented on it. On top of the fact it was even bored .010" larger (at .040" over.) than the lighter block at .030".
Conventional word say's the 509's are usually heavier?
I'd heard stories of heavier stock blocks occurring, but this is my first time out of maybe a dozen I've ever felt one.

I completely forgot to weigh them both, one short block is together now.
Next chance I get I'll weigh the 817 and check the date code.