ATK LS408 short block
Thread Starter
Staging Lane
Joined: Sep 2004
Posts: 62
Likes: 0
From: Hampton Roads, VA
ATK LS408 short block I am interested in ATK's LS408 short block (i.e. part number SP37, 24x, 10.8:1 with 66cc heads).
I have a 1999 Camaro LS1. I have not yet decided all of the details, but I will likely go with something like an AI cam and head kit using my factory heads.
Has anyone done a build with one of these ATK short blocks?
I have a 1999 Camaro LS1. I have not yet decided all of the details, but I will likely go with something like an AI cam and head kit using my factory heads.
Has anyone done a build with one of these ATK short blocks?
TECH Regular
Joined: Jan 2007
Posts: 403
Likes: 17
I havent really heard anything bad about atk shortblocks, but if your in the short block market, i would try thompson motorsports, they are about the same price as atk, great customer service and a great product.
TECH Apprentice
Joined: Oct 2008
Posts: 332
Likes: 0
From: North Carolina
I remember in a previous thread a Thompson engine blew, and they replaced it no questions asked after some investigation. That impressed me and I have heard they are good people to deal with, but I have no personal experience. I know ATK specializes in a lot of other engines also instead of just LS based. Me personally I would rather have a builder that just does LS stuff but thats my outlook.
Give Brandon a shout, he'll take care of you. He's a good guy and also a Vendor on here. https://ls1tech.com/forums/sponsor-s...lock-sale.html
Please give us a shout if you have any questions or if we can help you in any way with your needs for your stroker. We have some amazing 408CI Options all starting at only $3849 and the 1 year warranty that can not be beat.
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I literally just got off the dyno with my ATK 408. Everything has been awesome so far. Car made 819 to the wheels with 13# with a modified Huron Speed t4 kit and a cam specd by Martin. Plus it comes with a 2 year warranty
Thanks again for allowing us to be apart of your build.
EVERY engine we build no matter what product line (Import, Domestic, Performance, ETC) has NEW cam bearings. It is very common for someone to think they were used bearings in our short blocks because we do slide camshafts in them and spin them to make sure fitment is correct and this leaves witness marks, based on your post i'm positive its what you saw and assumed were used. Many shops make this same mistake.
If I recall it was a LQ4 408CI we did for Holley and The Custom Shop.
408CI
Manley Internals
10.1 Compression
Custom Comp Cam
GM Ported LS3 Heads
Holley Terminator EFI with dual TBI.
We originally had a lot of time to build the engine, but Holley kept messing up on the EFI Kit (was a prototype and we were the first to get it)...sending the wrong pinned harness which took a lot of time to figure out....was firing like a 4cyl, took a lot of fab work to get the linkage working so after all set backs it was literally a last minute deal and we didn't get to tune it...made about 630+HP 560+TQ and had a lot left in her with tuning...we just had time to make sure it would run while @ SEMA. John @ The Custom Shop will be getting time slips soon, but says it drives like a raped ape.
408CI
Manley Internals
10.1 Compression
Custom Comp Cam
GM Ported LS3 Heads
Holley Terminator EFI with dual TBI.
We originally had a lot of time to build the engine, but Holley kept messing up on the EFI Kit (was a prototype and we were the first to get it)...sending the wrong pinned harness which took a lot of time to figure out....was firing like a 4cyl, took a lot of fab work to get the linkage working so after all set backs it was literally a last minute deal and we didn't get to tune it...made about 630+HP 560+TQ and had a lot left in her with tuning...we just had time to make sure it would run while @ SEMA. John @ The Custom Shop will be getting time slips soon, but says it drives like a raped ape.
Sorry no build thread, no time. But will be posting up some info sometime the end of the month after I get my new trans
On The Tree
Joined: Oct 2010
Posts: 179
Likes: 0
From: Kansas City
I just got my standard ATK 408 shortblock installed and tuned. We're making slightly less power that the original LS3, but I did drop compression down to 10.3cr from 10.7cr.
I was hoping the increase in cubic inches would offset the decreased cr, but it fell short unfortunately.
All in all though, the car (only have about 500mi on it) appears to be running great with no problems. The only constructive feedback that I could offer is that the ship/build time was disappointing due to an over-zealous original quote for ship time.
I went with ATK simply because they were the best price I could find and their original ship quote was drastically better than the other quotes I researched. All in all.....I'm considering another ATK 415 shortblock for the GTO build in my signature below. I'm satisfied.
stock 317 with dual springs
turbo cam from Tick
NOS/Boost Ready Short Blocks
4.030 Bore LQ4 Block
Manley 4340 Forged Crank 4.000" 24 or 58 Tooth
Manley H Beam Rods with ARP 2000 Bolts
Manley Forged Skirt Coated Pistons (Customers Choice)
Sealed Power Hell Fire Rings / Total Seal CS AP Rings $100.00 upgrade
King XP Series Main/Rod Bearings
Durabond Cam Bearings
turbo cam from Tick
NOS/Boost Ready Short Blocks
4.030 Bore LQ4 Block
Manley 4340 Forged Crank 4.000" 24 or 58 Tooth
Manley H Beam Rods with ARP 2000 Bolts
Manley Forged Skirt Coated Pistons (Customers Choice)
Sealed Power Hell Fire Rings / Total Seal CS AP Rings $100.00 upgrade
King XP Series Main/Rod Bearings
Durabond Cam Bearings
