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post #1 of (permalink) Old 10-21-2002, 08:30 PM
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My \'89 K5 Is Slow

Hey i was woundering if anyone else has this problem with their '89 K5 Blazer. My engine, tranny, and gears are stock and i am running 33in BFG's with a 2in spring lift. My acceleration sucks and my tranny wont shift at anything over half throttle. Im thinking of putting 4.10's in her, but would be a waste of time. Help would be appreciated.
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post #2 of (permalink) Old 10-21-2002, 08:58 PM
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Re: My \'89 K5 Is Slow

what motor tranny and gears do you have now?
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post #3 of (permalink) Old 10-21-2002, 09:04 PM
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Re: My \'89 K5 Is Slow

700 R4-Trans
5.7l 350 EFI-Motor
Gears are stock maybe 3.73, not sure
i have [bleep] for acceleration and i wont shift unless i let off. It also shifts late. Over Drive wont kick in till like 65mph and it down shifts into 3rd at 60mph
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post #4 of (permalink) Old 10-21-2002, 09:08 PM
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Re: My \'89 K5 Is Slow

You probably have 3.08s.

Did you have the same problem with little tires?

You can use the RPO codes to find out what ratio:
Code Ratio
GU2 2.73
GU4 3.08
GU5 3.23
GU6 3.42
GT4 3.73
GT5/GT8 4.10

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post #5 of (permalink) Old 10-21-2002, 09:27 PM
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Re: My \'89 K5 Is Slow

yeap sounds like my friends blazer, my truck has 3.73's, it accelerates very well, my friend has 3.73's in his 89 suberban, it goes super fast, sounds like you need some 3.73's or smaller tires.
post #6 of (permalink) Old 10-22-2002, 07:13 AM
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Re: My \'89 K5 Is Slow

or a blown 540 merlin!! [img]images/graemlins/grin.gif[/img]
post #7 of (permalink) Old 10-22-2002, 11:53 AM
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Re: My \'89 K5 Is Slow

When you give it the gas does it start to shudder? My 92 Blazer did that and it would not start a few times. I went through a fuel pump, plugs, wires until I found out it was the dist. replaced that and it ran great.

Laters, Ryan
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post #8 of (permalink) Old 10-23-2002, 12:49 AM
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Re: My \'89 K5 Is Slow

Just like my truck does just add alot of vibration and rattleing. Ohh yeah my seat just ripped outta me floor. [img]images/graemlins/frown.gif[/img]
post #9 of (permalink) Old 12-11-2002, 12:21 PM
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RPO codes

My 75 had all the options spelled out on the sticker in glove box, but my 'new' 87 has a bunch of these RPO codes.

I have looked high and low for a listing of these RPO codes. Can you tell me where I can find them.

Thanks [img]images/graemlins/confused.gif[/img]
post #10 of (permalink) Old 12-11-2002, 12:39 PM
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Re: RPO codes

yeah, my buddys '85 (? I'm pretty sure) had the gear ratio listed in the glove box with all the option plain as day 3.73
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