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Swapping 4.3L with 350

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Old January 22nd, 2010, 12:37 PM
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Default Swapping 4.3L with 350

I've heard alot of different things on what it will take to replace my 4.3L with a 350 In my 89 GMC 1500 Sierra 4X4 5 speed manual. Both are tbi, will I need new harness, clutch? What else? I am also putting in new exhaust. and know about motor mounts and fan shroud. Thanks to all
Old January 22nd, 2010, 9:40 PM
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You can reuse your harness. The clutch will work IF it fits the 350 flywheel.
Old January 23rd, 2010, 11:11 AM
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Thanx
Old January 23rd, 2010, 7:59 PM
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I don't want rain on your parade, but last time I checked 350s are kicking out what? 180-190HP? The 4.3 Vortec puts out @ 265HP? Are you sure you'll be OK with the reduction in horsepower? (Since you asked.)
Old January 23rd, 2010, 8:48 PM
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If it's a 89 4.3, he doesn't have a Vortec, and it's a lot cheaper to build a 350. Plus we don't know his situation, the 4.3 is prolly tired, the 350 may not be as tired. thats my 2cents. I say drop a 572 to into that thing.
Old January 24th, 2010, 10:52 AM
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Yeah, it's easier to buy more bolt-on horsepower for a 350, too.
Old January 24th, 2010, 11:14 AM
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Yeh, plus with 35 inch tires I will get better gas mileage with the 350 who'd figure?
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