LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

LT1 vs SBC400

Old Aug 23, 2004 | 01:56 AM
  #1  
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LT1 vs SBC400

I have a Small block 400 from a 72 Impala in my garage, completely restored heads, all it needs is the block refreshed, crank turned, rods resized, and all the berings, and freezeplugs, to be a long block. My LT1 recent threw a rod, and to get it pulled refreshed reassembled and put back in it's about 1800 dollars(oy) or I can put the LT1 intake on the 400 and use the 76cc heads or whatever I haven't decided yet. My question is... will a SB406(.030, 400) out perform a LT1. Typically I would presume that more CI means more Power but I'm learning that's not always the case. I would appretiate any opinions. Thx
Old Aug 23, 2004 | 07:55 AM
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Re: LT1 vs SBC400

You can't readily bolt the LT1 intake to a 400. You will not be able to use the LT1 PCM to control the 400 because the 400 cannot be fitted with the Optispark. You will need a new crossmember because the motor mounts are different, etc. It is not a simple swap.

Rich
Old Aug 23, 2004 | 08:52 AM
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Re: LT1 vs SBC400

I see where you say the motor mounts are different. I am about to try and put an LT1 in an 89 Vette that had the regular sbc block. What will I need to do or is not a simple swap?

thanks
Old Aug 23, 2004 | 09:26 AM
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Re: LT1 vs SBC400

Originally Posted by RonnieW
I see where you say the motor mounts are different. I am about to try and put an LT1 in an 89 Vette that had the regular sbc block. What will I need to do or is not a simple swap?

thanks
Sorry, I am not very familiar with the 89 'vette.

Rich
Old Aug 23, 2004 | 09:47 AM
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Re: LT1 vs SBC400

You cannot run an LT-1 intake on a regular SBC heads because the manifold has no provision for a thermostat or water crossover.

-Dave C. '97 Z28
Old Aug 23, 2004 | 09:56 AM
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Re: LT1 vs SBC400

Originally Posted by rskrause
Sorry, I am not very familiar with the 89 'vette.

Rich
Wouldn't the differences between the sbc and ltl's be the same as any as far as motor mounts?
Old Aug 23, 2004 | 11:18 AM
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Re: LT1 vs SBC400

if you are using a corvette lt1 the mounts go in the same place because the a/c compressor is mounted high on the drivers side. if you are using a firebird or camaro lt1 the passenger side mount is set back and flipped upside down to allow room for the a/c compressor. the lt1 intake will not go on any other sbc due to the lack of coolant crossover and therm housing and manifold bolt angles are different too, i think.
Old Aug 23, 2004 | 07:11 PM
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Re: LT1 vs SBC400

http://www.lt1intake.com/services.htm
What about those...They're modified to go on a Smallblock Chevy... Maybe I was reading something wrong on their site.
Old Aug 23, 2004 | 07:29 PM
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Re: LT1 vs SBC400

Those will work.
Old Aug 24, 2004 | 01:53 PM
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Re: LT1 vs SBC400

Maybe I'm wrong but I thought chevy motor mounts were chevy motor mounts, I wasn't aware that they moved them around. At least my friends 96 Camaro mount points look like the same that are on my SBC motor
Old Aug 24, 2004 | 02:59 PM
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Re: LT1 vs SBC400

The bolt pattern for the LT1 motor mount is a little different. Doesn't mean you can't modify the mount to make it work, but it's not exactly plug-and-play.

As far as the block goes, it isn't much problem swapping it into an older chassis with the old mounts because there are extra holes for those mounts. So you may swap an LT1 into an older car without much hassle at all but putting a Gen1 into a new car will not go as smoothly. BMR makes a k-member for the swap though. Takes all the headache out of it, gives you more clearance and sheds some weight..... good idea.

Yes, the intake can be converted to work. You can also use a standard distributor with a little modification. TPIS also sells the Mini-Ram intake that'll work as well.

-Mindgame
Old Aug 26, 2004 | 01:02 AM
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Re: LT1 vs SBC400

Now for the other question, will a 406(76cc heads w/LT1 intake) out perform a LT1?
Old Aug 26, 2004 | 01:17 AM
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Re: LT1 vs SBC400

Originally Posted by SoloExceptional
Now for the other question, will a 406(76cc heads w/LT1 intake) out perform a LT1?
Maybe, by just a little. With all the money you ARE going to spend, is it really worth it though?
Old Aug 26, 2004 | 01:18 AM
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Re: LT1 vs SBC400

That's what I'm trying to decide, if the gain is actually worth the money it'll take
Old Aug 26, 2004 | 01:47 AM
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Re: LT1 vs SBC400

If you're using the smog heads off the Impalla, I doubt very much you're going to out perform the LT1.

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