OwieVT

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?

mikesimpalass

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.

WS6ICK2k

Texas Speed is also a good one to check out Ive also heard good things from Thompson.

Blackpanther99

iTrader: (8)

Never heard of anyone buying a short block from them.

Thompson Motorsports and TSP are good shops also as mentioned above.

WS6ICK2k

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.

Nwayne

iTrader: (3)

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

thompson

iTrader: (4)

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.

HCI2000SS

iTrader: (2)

Went with Thompson Motorsports myself. This is one of the best companies that I've ever dealt with

jrpimp00

iTrader: (17)

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

ATK Engines

iTrader: (1)

Thank you for your interest in ATK. Please let us know if we can help with any questions.

ATK Engines

iTrader: (1)

Glad to see you finally got her up and running Larry! Those are some nice numbers! Did you do a build thread at all?

Thanks again for allowing us to be apart of your build.

BlwnLs1GTO

iTrader: (12)

Edited.

ATK Engines

iTrader: (1)

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.

Sales@Tick

iTrader: (3)

ATK what is the run down on the combo in your avatar picture?

ATK Engines

iTrader: (1)

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.

jrpimp00

iTrader: (17)

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

nlpy8b

I'd like to know more about your setup...what heads, cam specs are you running. Did you customize your shortblock or run the standard shortblock. For example, did you upgrade to the ARP2000 bolts or upgrade the rings?

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.

jrpimp00

iTrader: (17)

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