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Building a 427 LS

Lucky 7.0L

By , Photography by

Summit Racing Equipment sent us one of its 6.0L bare blocks a while ago, tasking us to scrutinize it as the basis for a performance build, and more recently, Trick Flow Specialties shipped us its newly developed Gen X 255 heads for LS3 applications and an accompanying top-end kit. Their intentions couldn't have been more obvious: Use our stuff to build a killer combination.

Ironically, it's the combination several of our racer friends have been recommending. Start with a cast-iron 6.0L block, add LS3 heads, and match the cam to whether you're using a power-adder or not. Even if you build the thing wrong, it will be hard to not make 550 hp, naturally aspirated. Be frugal, and you won't spend too much money doing it, either.

Since we are building this engine completely from scratch, the final price may give some readers sticker shock. But we think this build is a good exercise in illustrating exactly how many parts are needed to build a modern LS engine, no matter what the displacement. It shows that you can literally build an entire LS engine with parts sourced from just a few aftermarket retailers, and finally it shows just how much money you can save buying used parts, or even buying a junk engine just to have all the ancillary items, such as fasteners, timing and rear covers, valley covers, and so on. You can build this same combination with a used 6.0L long-block, and it will cost you far less than ours did.

JMS Racing Engines in El Monte, California, handled the machining and assembly, and we will document the build in a couple of installments. This month, we dive into the block and stuff needed to put it together.

Parts

Description PN Source Price
Reconditioned 6.0L engine block SUMM-150105 Summit Racing $749.97
LS3 top-end kit TFS-K326-580-520 Summit Racing 3,199.97
Rotating assembly SCA-1-41930BI Scat 2,712.97

SOURCES
Trick Flow Specialties
1248 Southeast Avenue
Tallmadge
OH  44278
330-630-1555
www.trickflow.com
JMS Racing Engines
El Monte
CA
626-579-4567
www.jmsracing.com
Summit Racing
Akron
OH
800-230-3030
330-630-0240
www.summitracing.com/
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38 comments
Tom Igoe
Tom Igoe

double humps were awesome. Factory on vettes, 350 horse novas/chevelles, etc. Magazines want to tell us that its cheaper to buy a set of assembled aluminum heads compared to what we'd invest in getting a set of early double humps rehab'd, and the alum heads flow better.....but for the 300 dollars I have in rehabbing a set of doubles compared to 1200 shipped for a set of Chinese made alum heads, I feel I am just as competitive with them. They flow well, tight combustion chambers and are still made from heavy duty cast iron. Stick with 'em, dave.

David Welsh
David Welsh

Double humps really that bad? I have a set of 461's that came on the 350 I have, they're rebuilt and the engine runs, but I'm on the fence on replacing them with newer heads or trying to use what I have....looking for a hot street engine.

Rick Cherney
Rick Cherney

It's not hating, just fed up with throwaway motors that seem to not last. Build the piss out of it and get 800hp and blow up. WOW, anybody can do that with money. Build a motor to last more than 5,000 miles. Most motors that came in the cars will last 200,000 miles now with 450 hp. The magazine is selling parts to get people to buy the junk parts that last a year. By the way, LS = losing sucks, no matter what number you put behind it!!

Chevy Callahan
Chevy Callahan

then why did you come here? for attention? Haters.

Jason D Thompson
Jason D Thompson

All they're doing is building up a porcelain toilet. It will still get recalled after they build it. Hahahahaha

Larry Mickelson
Larry Mickelson

Build one to help our gas powered trucks tow our cars to the track!

Tom Igoe
Tom Igoe

oh boy! another giga-buck LS build that we cant afford to build ourselves! GREAT job on alienating your readership. I guess ill just go put together an LS-murdering 383 stroker in my garage using junk double hump heads, a 4 bolt truck block, used 400 crank and 800 dolars worth of machine work and new gaskets.

Pedro Perez
Pedro Perez

Camero craft is super boring doing same builds over and over and over always an ls1, finish the damn thing already

Dan Edwards
Dan Edwards

Oh great, another LS build, because we never get to see LS builds.

Bob Maasen
Bob Maasen

Flat head ford forever . p.s.On the bench,

Nick Yansky
Nick Yansky

Thanks for this. Bookmarked for my escalade build!

Nitt Alas
Nitt Alas

I think the LS build has been done before. A LOT. Boring.

Art Kester
Art Kester

kind of like a super mousemotor?

Lee Smith
Lee Smith

just finished rebuilding a block myself. those internals can knick u real good (thats not good) if not carefull.. and gloves mainly

Abdelah Souhair
Abdelah Souhair

Controle la cou rsse poin mor pas et poin mor haut de chemise

Abdelah Souhair
Abdelah Souhair

Controle la coursse poin mor pas et poin mor haut de chemise

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