Anyone know what this engine is from?

[69LM1]

I am looking at another supposed 69 vette 427 engine and here are the numbers, can anyone add anything to this? The deck numbers seem off.

BTW- The "other" block turned out to be cast, not aluminum!

427
Block Casting 3935439
deck TO5282BY (maybe a H after, or a smudge)
Hi Perf Truck/Pass on the back
and CONV2 longways cast into the rear by the GM, what does that mean?

Heads
rh: 3873858 f226 hi perf
lh: 3873858 f176 hi perf

any thoghts and or comments would be helpful.

Rich

[jfkheat]

Block is a 68-69 427. Heads are 66-67 L78 and L72 Sq Port, June 1966 casting date. Can't find the BY code in my book. The only ones I see with a B are police or big Chevy blocks. You might need to look at the deck #s again. Is it a 4 bolt block?
James

[WILMASBOYL78]

casting # is for a 427 68 to early 69. Cylinder heads are 66 pass,chevelle or vette 396/427 hi perf motors. As for the letter code on the block stamp seems like you have too many digits. Is there a vin stamp?