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Is there a big difference between the 3400 LIM and 3500 LIM? The reason for asking is I am trying to collect parts for the new hybrid motor and I know everyone says how much better the 3500 upper is. Since I will be using a custom UIM/plennum to fit the 75mm TB I didn't know if I needed to locate a 3500 LIM. The heads I found are 170 castings from a '99 3400 if that makes a difference.
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From what I have read, the 3500 ports are different than the 3400, whihc means they won't match up, in a similar fashion that the 3400 intake will not match the 3.1 (genII) heads. -
One other note is you can't run 3500 heads to match to the 3500 lower if your starting with a 3100 or 3.1 block. The bore and head gasket needed is too small for the combustion chamber on the 3500 heads.
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3500 Build, Comp XFI Cam 218/230 .050 dur .570/.568 lift 113LSA
Fully Balanced, Ported, 3 Angle Valve Job, 65mm TCE TB, S&S Headers.
Stage-1 Raybestos/Alto 4t60e-HD, EP LSD, 3.69FDR
12.61@105 Epping NH Oct 2015 Nitrous 100shot (melted plugs) 13.58@98.8 N/A 3200LBSComment
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Yup stick with the lower intake manifold for the heads you have. Or you can use a 2000+ LIM too as it's large port.
There isn't much difference that I can see from viewing pics on line between 3400 and 3500 lowers. They both look like the "large port" runners. Not sure if the 3500 is larger inside and opening to the head or not. But the 3500 lower won't match to 3400 heads. It's only the upper's that can be swapped around.sigpic
New 2010 project (click image)
1994 3100 BERETTA. 200,000+ miles
16.0 1/4 mile when stock. Now ???
Original L82 Longblock with LA1, LX9, LX5 parts
Manifold-back 2.5" SS Mandrel Exhaust. Hardware is SS too.
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Sorry if there was any confusion, the 170 castings are 3400 aluminum FWD heads. I just didn't know if the 3500 LIM is better, and will be ported so if the missalignment was slight could be corrected. Since it seems as the 3400 LIM will be easier to use without disadvantage, that is what I'll do.
Thanks!Comment
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3100's are abundant in local yards and can be had for cheap, is that lower the same? Sorry about the questions, but I am unfimiliar with the tranverse engines.Comment
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Don't use a 3500 lower. I don't even think the bolt holes are the same...
You got 3400 heads, good. You need 96+ 3400 LIM, OR a 2000+ 3100 LIM.
The 94-99 3100 stuff is small port. Avoid that as the ports/casting is tiny and can't be ported to even 3400 stock.
Check for Vans for the early 3400's if no late model cars are available there.
3100's to avoid will have more than 6 bolt holes on the top of the LIM, and the small port 3100's can be identified easily as they have lines on the top of the plenum. If you see those motors keep walking.sigpic New 2010 project (click image)
1994 3100 BERETTA. 200,000+ miles
16.0 1/4 mile when stock. Now ???
Original L82 Longblock with LA1, LX9, LX5 parts
Manifold-back 2.5" SS Mandrel Exhaust. Hardware is SS too.
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The 3500 LIM will not bolt to the 3400 heads, so you are stuck with the 3400 LIM if you use the 3400 heads.Originally posted by ForcedFirebird View Post
Since you have a RWD car I think it would be cool to use the plenum from a 3400 Equinox which is very similar to the 3500.
Equinox Plenum
2000 Grand Am GT
2011 Chevy Impala
"The world's best cam combined with a poor set of heads will produce an engine that's a dog. But bolt on a set of great heads even with a poor cam, and that engine will still make great power." ~John LingenfelterComment
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I'm going to use a manifold similar to this from boostedrs :
http://60degreev6.com/showthread.php?t=35562&page=2
And one of the TB's from ryan hess :
http://60degreev6.com/showthread.php?t=34483Comment
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Here is a 3500 LIM gasket on a 3400 head
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and a 3500 LIM gasket on a 3400 LIM
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The bolt holes are the same but the port shape and location changed quite a bit. I'm afraid port matching is not an option.Comment
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Tastey, raised ports.Comment
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Where did your pics go? I got some 3500 heads here and just by measurment alone, I'm not seeing itOriginally posted by Superdave View PostHere is a 3500 LIM gasket on a 3400 head
and a 3500 LIM gasket on a 3400 LIM
The bolt holes are the same but the port shape and location changed quite a bit. I'm afraid port matching is not an option.
. I'll probably get an upper end gasket kit for the 3500 heads, but I need to get the 3400 heads sent to the buyer...
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server died in a power outage last week... the webdrive is still intact but apache won't start.. hopefully i'll have it back online early next week.
here are the 2 pics though..
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Fantastic! Thanx.
It appears that GM almost reversed the shape from top to bottom on the 3500 heads, but I kept comming up with almost identical measurements.
BTW, where have you been getting your 3500 gaskets? FelPro hasn't started making them yet (I was hoping to get Severe Duty), guess I have to go to GM?Comment
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yep, from GMpartsdirect.com it's like $135 for the whole kit.Comment
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