If money is there... LSX IMO :yes:

400's are hard to find in decent shape any more.

 

I agree with Doug. it is more than just an engine to do the swap. fuel tank, pump, lines, modding the engine mounts to accept it etc... it will get expensive.

A nice 400 will make killer power and cost a fraction of the lsx.

 

I really like the Dart short blocks since most are ready for work....but the LS motors are hard to beat for ease on HP/TQ along with MPG. Sound mild at 500HP Vs. a old school @ 500HP.
But again $$$$$$ for the upgrades Vs. a Gen 1 block.

 

I'd go with a 400 myself - get a retro hydraulic roller cam, some good heads and you can be at 500 HP pretty easily in a very tame driving car with much less work for the conversion.

 

Less work, I agree, but I'm not sure less money.

I don't know about you, but when I get done paying for block machining, a good forged bottom end, oil pan and pump, hydraulic roller valve train, good heads, intake and carb, I'm always at about $6,000 or more in the engine alone. Then add in headers, accessories, etc. and you're looking at another $1,000 plus depending on how fancy you get.

For $7,000 you could probably have a really nice LSx engine in your car - you're just spending the money on different things - LSx pullout with harness, ECU and accessories, probably an accessory bracket or two, maybe an oil pan, fuel tank and fuel line plumbing, adapter motor plates and headers, maybe ECU tuning if you change cams.

The thing is, as compared to the 400, the LSx will take 100 pounds off the front end, have good street manners, deliver good fuel economy, will work well with an overdrive transmission and have a lot of room to grow for additional NA or FI power.

 

You are right on with the price to do the 400sbc I have figured 6500 to 7000. I'm down to a bare frame right now and will be replacing most of the parts with new. It has been sitting for 20 years (I know). So it does not sound like it would be to much more money for the LSx conversion parts if any. Will be getting new mounts, fuel tank, fuel lines, etc. no mater if it is for the 400 or the LSx. What is the best to look for LS1, LS2, LQ9, or ??

Thanks

 

How much do you wanna spend? Is this a budget build or all out?

 

I have started on the build. Here is what I have already. C5 brakes front and rear, 9" rear with 3.50, HOtchkis springs and leafs, Bilstien shocks, SC&C upper control arms and outer tie rods, will have hydor boost system and lee power steering box. No tranny yet. would also like to be in the 500hp range.

 

Are you looking for a manual or automatic transmission?

500 hp at the flywheel with an LS2, LS3 or L92 isn't difficult or terribly expensive.

 

manual.

 

t56!

 

I'd definately go Ls if $$ is not an issue. I was thinking of doing the same except for the fact that I already have a samall block with AFR heads, super comp. headers air gap manifold and a full msd system so at this piont unfourtunately I'm thinking of just getting a GM 383 short block or maybe a Dart 400ci. The more displcement the better.

If I was starting from scratch I'd do up a nice Ls-2. The Gm performance parts catalouge that I downloaded online lists all different type of of block,cam,head and intake combos with expected hp and tq. check it out.

POWER​

PACKAGE​

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John, looks like the best way to go for hp and $$ would be the LQ9 or LY6? What about the best place to get the T56?

 

You know with everything there is a gift and curse........

The only thing with the LY6 yes it comes with the L92 heads, but it has VVT(Variable valve timing ) but no sweat.... not too bad to change
and easy on the pockets since your getting another cam anyways.....
read this about the VVT swap....
http://www.chevelles.com/forums/showthread.php?t=216205&page=3

If you want to bump the comp up, shave the L92's down to .010-.030...
Make sure to watch your piston to valve clearance.......

here is some more info on stock 6.0 bottom ends with L92 heads and different cam combos
http://www.ls1gto.com/forums/showthread.php?t=286447

The T56, I am tapped out on info.... I m an autotranny guy I run a 4L65E

 

I'd be looking for a complete LSx-T56 takeout.

 

So Vette, GTO, Camaro, TA, or SSR

 

yelp for a T56

• Chevrolet Corvette, 1997–2007
• Chevrolet Camaro, 1993-2002
• General Motors GM F platform V8 cars, 1993–2002
• GM M12
  • 2001–2004 Chevrolet Corvette Z06
  • 2004–2006 Pontiac GTO
  • 2004–2006 Cadillac CTS-V
• GM MN6
  • 2004–2007 Chevrolet Corvette
• GM M10
  • 2005–2006 Chevrolet SSR
  • 2006–2008 Holden VE Commodore
• GM MZ6
  • 2005–2007 Chevrolet Corvette Z51
• [Pontiac Firebird/Trans Am], 1993–2002

If you are in Dallas, I found a few for ya in the junkyards with low miles......
www.car-part.com

 

yelp for a T56

• Chevrolet Corvette, 1997–2007
• Chevrolet Camaro, 1993-2002
• General Motors GM F platform V8 cars, 1993–2002
• GM M12
  • 2001–2004 Chevrolet Corvette Z06
  • 2004–2006 Pontiac GTO
  • 2004–2006 Cadillac CTS-V
• GM MN6
  • 2004–2007 Chevrolet Corvette
• GM M10
  • 2005–2006 Chevrolet SSR
  • 2006–2008 Holden VE Commodore
• GM MZ6
  • 2005–2007 Chevrolet Corvette Z51
• [Pontiac Firebird/Trans Am], 1993–2002

If you are in Dallas, I found a few for ya in the junkyards with low miles......
www.car-part.com

Not any of the Corvettes - they all use a T56 that has been adapted to be mounted to the rear IRS. In that application the T56 is missing, at a minimum the tail shaft housing. I'm not sure how hard or easy it is to convert a Corvette T56 for use on a regular bellhousing.

Also not a pre-1998 (I think) F-body, those were LT1 cars.

 

Man you guys are great!! I found these also, would have to get T56 seperate.

http://dallas.craigslist.org/search/pts?query=ls1&catAbbreviation=pts

http://dallas.craigslist.org/dal/pts/1683721159.html

http://dallas.craigslist.org/dal/pts/1666300755.html

http://dallas.craigslist.org/dal/pts/1680724650.html

http://dallas.craigslist.org/dal/pts/1680683317.html

 

I think I can get LS2 and T56 pull out for less then the 7000 I would pay for the 400sbc. Less hp to start with but for the 7000 that does not include tranny and additional items I would need, so would have the extra money to put in to the LS2. what you think?

 

Depending on the mileage that's a fair price. Wander over to LS1tech.com and do some reading. The LSx engines respond extremely well to cams and, depending on how much you want to spend, you can get the factory LS2 heads ported for even more power. The LS2 will also accept LS3/L92 heads which flow very well from the factory or, again, even better with a port job. (You'd have to swap intakes with the LS3/L92 heads.) Any way you go, you're going to have fun!

 

Check this out:
http://www.ls1tech.com/forums/conversions-hybrids/1078185-6-90s-junkyard-6-0-a.html

Pretty damn good for a junkyard combo..... or should I say "recycled" Engine builders hate to see this....

 

I'm in the same predicament deciding between the 400 smallblock and a carbed and cammed, possibly different headed LQ9. I am very concerned about the cost of the change-over. I think salvage yards have caught on to this craze and the prices have gone up considerably and I'm not crazy about using a computer controlled tranny, would rather stay with a 700R4 or similiar. Any advice on the swap and what it would take on the wiring side if I kept it carbureted besides the coil controller? Recipient is a 1972 Camaro with a 406 in the engine bay now.

 

What made you choose a Chevy 400 SB ? I am running a 400 SB, but just stock. I'm glad to hear that it can be upgraded to that much horse power !

 

The 400 is a fantastic starting point for a small block chevy, you can literally trip over them in the garage and make 450 horse and as much torque. Get a little more cam than you would run in a 350 and decent heads and away you go.
My 406 ran 11.40 all day long on steel wheels full interior and PB, PS. 100% street trim. I would have rebuilt another one had I not scored a deal on the motor I have now.

I would rebuild the 400 if I had a good one before the LS conversion but thats just me. LS motors are a sweet deal but not the only way to skin a cat .

 

I went with a 400 SBC because I had a lot of small block stuff I was going to reuse like headers, exhaust, dizzy, etc. You can see in my sig though that I went with an all new assembly and then wound up replacing all the stuff I was going to reuse as well. With what I have in it, I wish I had gone ahead and done an LSx combo.

Also as far as the LS engines pulling down low, they do that because of the EFI. Throw a carb on them and I don't think they'd be much different than a small block in normal low speed driving. Actually, I think small blocks are better at low speed torque than the LS when you're looking at comparable engines if that's what you're looking for. The LS's make the HP because of how well they flow up top. For instance, Mast makes a 413ci 605hp LS3 that makes the same torque as my 500hp 400 SBC, and mine just slaughters it below 4000 RPM but I bet the LSx is more efficient. Since I have a crude EFI system I can pull my 0.64 OD and 3.42 rear at 40mph or around 1200 RPM, I can even set the cruise control about that low and not have issue unless the grade is steep. You reach a point normally aspirated where you're going to make the same peak torque per ci across engine platforms, one is just going to be better about putting that out higher up or across a better power band.

However, like I said I still kind wish I had gone LSx. I think if you ever reach the point where you're truly satisified with what you've got, it's about time to get out of the hobby. Not that you have to always be changing stuff but come on, who here doesn't have a case of the wishes every now and then?

 

In this economy you need to save your money wherever you can and reusing good parts is smart. Although the LSX would be a beast i think you'd have just as much fun with the 400. Good decision IMO.

 

For the street, once you start approaching 500hp/500 ftlb torque with typical street tires it doesn't matter too much, too hard to get it to the pavement so you spin. The LS with EFI will probably save a bunch on gas for you though.

 

I was going thru this same thing, rebuild the old 350 shortblock i had or do a LS based engine. I desided to do a LM7, 5.3 out of a truck, putting a cam in it and converting to carb. the motors are around dirt cheap, make plenty of power for what i want, and people say they last forever (like i am ever going to put a million miles on the car anyway).

Scott