what EXACTLY do I have here?
Thread Starter
Burning Brakes
Joined: Mar 2005
Posts: 861
Likes: 0
From: WNY
what EXACTLY do I have here?
I bought somethings from a friend on a completely random flier. Not going to go into the long story of how my buddy came into possession of these.. but he asked me the other day if I wanted to buy them. They were two big block chevy motors.
Anyways, i went ahead and took them - They both were 'known good'.. they ran when they were pulled a few months ago. He didnt think they were the original motors for either vehicle.. I paid next to nothing for them, basically just got them out of his shop. They were so filthy and nasty that you could not read the block codes on either of them. I finally got around to scrubbing off the pad and checking the codes under the valve covers and Im a little surprised... They are identical. Same heads and blocks.
So here is my question - What exactly do I have here? I have a general idea that they are a decent block and that a lot of people like the oval ports.
Blocks - 3999289
Heads - 336781
Thanks for any input.
Anyways, i went ahead and took them - They both were 'known good'.. they ran when they were pulled a few months ago. He didnt think they were the original motors for either vehicle.. I paid next to nothing for them, basically just got them out of his shop. They were so filthy and nasty that you could not read the block codes on either of them. I finally got around to scrubbing off the pad and checking the codes under the valve covers and Im a little surprised... They are identical. Same heads and blocks.
So here is my question - What exactly do I have here? I have a general idea that they are a decent block and that a lot of people like the oval ports.
Blocks - 3999289
Heads - 336781
Thanks for any input.
Thread Starter
Burning Brakes
Joined: Mar 2005
Posts: 861
Likes: 0
From: WNY
Also, I should add the reason I bought them was that they were running BBC's. I figured I could spend a few bucks cleaning them, new gaskets, compression test them, and put on a few dress up parts and sell them for a pretty good profit on each.. but now that I know what they are (I figured they were 390's or a worse factory block), Im considering fully rebuilding/reworking one and swapping it for my 383 in the current car..
Cruising
Joined: Apr 2011
Posts: 11
Likes: 0
From: Dallas TX
http://corvettec3.ca/casting.htm
72-73-74. i was actually thinking of a big block for my 73 since I have a spun bearing in my factory motor. Still debating on keeping it numbers matching or going crazy on with it. I might be interested in one of those.
72-73-74. i was actually thinking of a big block for my 73 since I have a spun bearing in my factory motor. Still debating on keeping it numbers matching or going crazy on with it. I might be interested in one of those.
Last edited by kingjason1; Apr 22, 2011 at 11:50 PM.
Thread Starter
Burning Brakes
Joined: Mar 2005
Posts: 861
Likes: 0
From: WNY
http://corvettec3.ca/casting.htm
72-73-74. i was actually thinking of a big block for my 73 since I have a spun bearing in my factory motor. Still debating on keeping it numbers matching or going crazy on with it. I might be interested in one of those.
72-73-74. i was actually thinking of a big block for my 73 since I have a spun bearing in my factory motor. Still debating on keeping it numbers matching or going crazy on with it. I might be interested in one of those.
Let me know if your interested, Im just north of Tulsa so not a long trip get one of them.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Both engines should have an engine ID code and a VIN derivitive stamped on the pad on the block at the front of the right head.
Clean off the pads and see what you find.
Clean off the pads and see what you find.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
So according to that referenced website, we have a match!
1974 Corvette
454 - 275 HP LS4 3999289 336781
It would be interesting to see if there is a vin derivative on the engine pad to see if they were original equipment.
1974 Corvette
454 - 275 HP LS4 3999289 336781
It would be interesting to see if there is a vin derivative on the engine pad to see if they were original equipment.
Thread Starter
Burning Brakes
Joined: Mar 2005
Posts: 861
Likes: 0
From: WNY
I'll post the vin stamps and stuff on the front after I get it cleaned off. Im serious when I say they are COVERED in grime. I may have misread the heads on the second one also, it wasnt well lit at the time and hard to read.. I'll post up some pics later as well.
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Thread Starter
Burning Brakes
Joined: Mar 2005
Posts: 861
Likes: 0
From: WNY
Well I have some pics.. and unfortunately feel a little let down.. lol.
the 'cleaner' block that is on the stand has an engine ID of t0518TRK and the head casting date ends in a 77... so it looks like it is out of a 78 pickup truck... kind of funny that the exact same heads/block were used for both the 74 vette and a 78 pickup. According to a site I found it looks like its an LF-8.
The nastier looking block with the auto transmission attached is a casting t0309trh that one is the same block but a 353049 set of oval ports with a 73 casting date on the heads.. So looks like an LS-4 still at least.
Its kind of funny.. they match this very well:
73 Corvette:
454 - 275 HP LS4 3999289 353049
74 Corvette
454 - 275 HP LS4 (late) 3999289 336781
But from what I can tell are actually these:
TRH 1973 454 240 Truck LS-4 VIN Z, L, 10, 20
TRK 1978 454 250 Truck LF-8 VIN S, fwd
Someone correct me if I'm wrong on that..
I used this site to decode:
http://www.chevy-camaro.com/chevy-ca...es.asp?group=6
Anyways nasty pic time! my shop is a disaster at the moment since we just did a remodel project so ignore the mess.. lol
the 'cleaner' block that is on the stand has an engine ID of t0518TRK and the head casting date ends in a 77... so it looks like it is out of a 78 pickup truck... kind of funny that the exact same heads/block were used for both the 74 vette and a 78 pickup. According to a site I found it looks like its an LF-8.
The nastier looking block with the auto transmission attached is a casting t0309trh that one is the same block but a 353049 set of oval ports with a 73 casting date on the heads.. So looks like an LS-4 still at least.
Its kind of funny.. they match this very well:
73 Corvette:
454 - 275 HP LS4 3999289 353049
74 Corvette
454 - 275 HP LS4 (late) 3999289 336781
But from what I can tell are actually these:
TRH 1973 454 240 Truck LS-4 VIN Z, L, 10, 20
TRK 1978 454 250 Truck LF-8 VIN S, fwd
Someone correct me if I'm wrong on that..
I used this site to decode:
http://www.chevy-camaro.com/chevy-ca...es.asp?group=6
Anyways nasty pic time! my shop is a disaster at the moment since we just did a remodel project so ignore the mess.. lol
Thread Starter
Burning Brakes
Joined: Mar 2005
Posts: 861
Likes: 0
From: WNY
I knew they were in trucks, but they were not in the 'correct' trucks. Actually both trucks that these were in were salvaged - thats the reason the distributors were smashed - they were ruthlessly cut out in a hurry. Actually both motors still have FRAME attached to the mounts where they were cut loose. lol
Safety Car
Joined: Sep 2005
Posts: 4,060
Likes: 101
From: Southeast, Tennessee
St. Jude Donor '09 thru '26
i had a 73 454 impala engine in my 71 el camino and about the only thing i can tell you about them is that they are really a weak big block. remember it was during that time that all the manufacturers were fighting the EPA (not to mention the first arab oil embargo) so they really strangled those engines.
