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81 Coupe DeVille 4/6/8
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Discussion Starter #1
I have an idea, I'm sure someones thought of it already. The 368 and the 500 are the same block right? So I should be able to put the Eldabrock inatke and cam they make for the 500 on my 368, right? Or are the lobes to big for a 368 sense it wouldn't need as much air/fuel? Then get the heads machined and ad a high output coil on my HEI. Also I should be able to send my computer of and have it reprogramed for more performance. Also couldn't they make the computer run only 4 and 8 cylinders and skip the rough running 6 mode? I should get decent power with this set up right.
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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All that should work in theory. Dunno about the computer reprogramming though. Still, a bone stock 500 would outrun a cammed 368 w/ an Edelbrock intake, so if I were in your position I'd go that route. Maybe an MT3 fuel economy cam if you're so inclined, and if you're feeling real ambitious try adapting the 8-6-4 rockers to the 500 heads (at least 1 person is attempting this as we speak.)
 

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81 Coupe DeVille 4/6/8
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230 Posts
Discussion Starter #3
Okay, 500 4/6/8 would work. How much does that cam and intake package add? Anyone know?
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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7,971 Posts
On a 368? Dunno. On a 500 I'd guess around 20-25 for the intake. There's not just ONE cam grind availible for these engines, obviously. I'm not familiar with / aware of an Edelbrock cam. But with, say, something common like an MT15 (or another brand with similar specs) and an Edelbrock intake I'd say 360-370hp, still around 500ft.lbs. Would be a good idea to add headers at this point.
 

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2005 Escalade 6.0L 2WD, 2007 Jeep Grand Cherokee Limited CRD
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I'm pretty sure the head ports are smaller on the 368, so unless they are opened up, the Edelbrock intake wouldn't work right on a 368.
 

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1976 Fleetwood Brougham d'Elegance, 1990 Allante
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Speaking from my personal experience, this isn't worth the effort - working with the 368 is more than a little tough. You're going to run into a couple problems with the Edelbrock manifold on this engine:

There is no adapter to attach the three-bolt DFI throttle body to that manifold. You'll most likely have to switch it over to a carburetor (650-750 CFM), which presents a second problem: the FI in-tank fuel pump will flood your engine and possibly damage the carb, so you'd need to pop it out and put a lower-pressure one in. I tried to avoid that by using an expensive Edelbrock regulator, but it didn't regulate well enough and the engine kept flooding. Of course, once you do that there's no need to send the computer off for reprogramming.

By this point, your're going to need to lose the factory exhaust if you want to keep making lots of power. The FI doesn't like duals, but with a carb you could run 2.5" duals with no problem.

For the 4/6/8, I personally would put them on a switch so you can manually control whether it's running on 8 or 4. It shouldn't be too hard to do, and the computer isn't always the best at managing that system.

If you start with that, you should be able to turn the 368 into a pretty good engine. I have to recommend, though, that you lose it altogether and get a 500 - they have lots more potential.

- Joe
 
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