BB Crate Engine ID

[Mike S.]

A friend purchased a 66 L72 coupe today. He mentioned that the seller also had a 454 engine for sale, still in the crate. The seller had received the engine in a complicated trade and knew little about it. My friend said the casting number was 14015445, which I interpret as a 78-90 454 with 2/4 bolt mains. The Chevy part number, 3965774, was still attached, as were stickers indicating "special service engine" and the use of at least 100 octane fuel was required. There was no intake or water pump, and the engine was painted black.

Any idea of what this is?

Thanks,

Mike S
#33053

[Clem Z.]

Re: BB Crate Engine ID

it is a LS-7 12.5:1 compression 454.

[Clem Z.]

correction it was 12.25:1 CR *NM*

[Craig S.]

Re: BB Crate Engine ID

Mike - as Clem mentions, it's an LS7. This is basically a 454 version of the L88 427 powerplant that was never actually delivered in a production car. It has a lot of Chevy's good guy parts for internals, but would not make for a driveable street engine. I have a crate LS6 I plan to use in my 74, which is a somewhat similar engine (same block casting, by the way, it will be a 4 bolt main cap engine), similar crank, I belive yours is 5140 steel (better) tuftrided, mine isn 1053 steel tuftried, both of course are forged steel. The rods are the same, GM 7/16" dimple rods, both I believe with knurled shank bolts versus the L88 boron bolts (I may be wrong on the LS7 but I think the crate LS7's got the same bolts as mine). The other main difference is those 12.25 to 1 slugs, vs my 11:1 slugs, and the L88 cam vs my mechanical 4362. All of the specs for this engine are in some of the early 90's performance parts catalogs....when GM sold this over the counter crate engine. I may be wrong, but it seems they are also in some of the older GM power books...Craig

[Mike S.]

Thanks Guys! *NM*

[Joe L.]

Re: BB Crate Engine ID

Craig-----

Just "peeking in" from my travels in the east. Yes, both the crate LS-6 that you have and the crate LS-7 described were equipped with the knurled shank rod bolts. These bolts are also used for all Gen V and Gen VI big blocks, too. Only L-88/ZL-1 got the boron steel bolts and special rods. These rods and bolts are still available from GM. However, the price does not justify their use since better aftermarket parts are available for a lesser cost.

[Jim T.]

Re: correction it was 12.25:1 CR

Clem several years ago I knew of a person that had three LS7's sitting in the crate in his garage. Wonder what the worth of one is in todays dollars?

[Clem Z.]

Re: correction it was 12.25:1 CR

the only use for these hi comp engines is the race track and there different crate engines out there now for track racing with newer technology so i guess the value would be in the eyes of the beholder. i also know several people with these engines still in the crates. if you want to build a drag race car for ET racing they would be a good engine for that. i do not remember what they sold for back then but i am sure you could turn a profit now days.

[Craig S.]

Re: BB Crate Engine ID

Thx Joe - Actually, I was thinking of using the ARP2000 bolts in my LS6 if I pull it apart to balance it more carefully, like I used in the same dimple rods in my 66 L72 I am building up. Hard to beat ARP's fasteners in my book. I saw the L88 rods and bolts too....seemed way out of line compared to the 8 pack dimple rod kit. If I recall, the rods themselves are the same, other than possibly the L88 rods were shotpeened? Just curious what GM did differently between the white and green rods other than the boron bolts...Craig

[Joe L.]

Re: BB Crate Engine ID

Craig------

The LS-6/7 rods and the L-88/ZL-1 rods are completely different forgings. The latter are considerably beefier. Just how much stronger they actually are, I don't know. Still, they're not worth the cost considering that there are much stronger aftermarket rods available for a comparable price.

[Craig S.]

Re: BB Crate Engine ID

Thx for the input on that Joe....Craig