5.8 swap

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Jul 6, 2013 | 06:32 PM

shoe4849

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Joined: Jul 2013

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5.8 swap

found an old 81 5.8 with 20k original miles
is it possible to install into a 91 f-250 with a 5.8
will the intake from 91 bolt to 81 block and 81 block to 91 auto transmission

Jul 6, 2013 | 06:36 PM

Sapphire Blue_95

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Joined: Apr 2013

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From: Dawsonville, Georgia

The 351 up to 87' had a carb. Your 90 has a computerized fuel injection system. It can be done, but first, your going to have to get rid of all of the computer components in your current truck.

Jul 6, 2013 | 08:08 PM

cjben

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Joined: Apr 2001

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From: Midwest

or you could swap the computer and other things onto the 81 motor but I'm not sure the 81 cam would be computer friendly and the 81 heads aren't as good as the heads on the 91 engine.

Jul 7, 2013 | 08:04 AM

Conanski

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Joined: Jun 2006

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From: Ottawa, Ontario

Externally the 351/5.8 engine has not changed since 1971 so all the EFI stuff will bolt right on that motor, but that '81 is a low compression smog era motor so it'll make even less power than the '91 it's replacing.