decoding my engine numbers

[70MCx2]

I am rebuilding a 454 to swap out with the one in my '70, and have some questions about the info I found on the block. It has "H Per Pass F4" on the rear end, along with F28-79 and 14015445, all cast into the block. If I'm correct, I think the 14015445 is the casting number, and that reveals a "1978-1990 454 2 or 4 bolt main", and F28-79 shows it to have been cast on June 28, 1979. But, I don't know what "H Per Pass F4" is. High performance, maybe, but what does that mean, and the F4?

 

The engine number is even more confusing, and it looks different than any of the others (few) I'e seen. It's stamped on, but look like smaller letters than the others I've seen. The best I can tell, it is "080 010 ?1?", with the ? marks representing either a partial 0 or what looks like a backwards C. Maybe a replacement or crate motor of some type?

 

[Sam (Bones)]

the engine code stamping on a '79 454 should be above the timing cover on a small machined area, the VIN will be stamped on the deck by the head

[70MCx2]

I found the engine code - T07119XJ - where you described, and am about to go try to decode it.

 

What I described as the engine code must be the VIN, as I found it where you described. It was a very poor job of stamping, as two of the numbers are incomplete, as I don't think they would use a backwards 'C'.

 

Still trying to 'figger out what the "H Per Pass F4" and "GMT12" casting numbers are all about.

[70MCx2]

okay, so now I'm REALLY confused. The block casting tells me it's a 1975 (or 1978, depending on site) to 1990 454. When I found a list of engine assembly code suffixes, all of the ones that were Xsomething were 396's, and there was no XJ even shown.

 

Also, the number that is on the pad on the right front, in front of the cylinder head, doesn't appear to be a partial VIN, as it does not begin with 1 for Chevrolet and doesn't have a letter for final assembly plant plus the last six of the VIN. Instead, it has 9 numbers, in 3 groups of three (080 010 010). This number looks as if it might have been put there as a replacement number, but the engine assembly code looks original.

 

Any suggestions?

[Sam (Bones)]

by what you've given us it's a 1979 engine

 

the H per pass is on all big blocks, it stands for high performance passenger

 

your code is 9XJ which is a 1979, 454/245HP marine engine LF-8

 

http://www.nastyz28.com/gm-chevy-codes/chevy-engine-codes-suffix-11.php

[70MCx2]

Thanks for the info. I came across that website when I was looking, guess I didn't dig deep enough.

 

The numbers on the pad where the VIN goes makes me think that the engine was put back into service as a short block; I'm guessing that the VIN was machined off and then it was restamped with the "080 010 010". The heads are slightly different, one is a '72 and the other a '75, so that also makes me think it's been rebuilt. Looks like I will be rebuilding the block and replacing the heads with rectangular ports.

 

Thanks again for the help.

[Sam (Bones)]

I wouldn't use rectangle ports for a street engine, don't under-estimate the power you can make with ovals!

 

some over the aftermarket ovals are just awesome!