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injector size question

Old Jan 30, 2008 | 09:51 PM
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Default injector size question

I'm in the process of picking out the heads for my 5.3 H/C build. and I was wondering how do you know what size injectors i will need.

I'm looking at the ET performance 215cc heads and the AFR 205s. I noticed closet redneck is running 48lbers on his 5.3.

What are the biggest "plug and play" injectors for our trucks?? marine 8.1s??

I would like to stay plug and play, but if I need to, I can re-wire the connectors.

Thanks
-Joshua
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Old Jan 30, 2008 | 10:05 PM
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Originally Posted by joshua022
I'm in the process of picking out the heads for my 5.3 H/C build. and I was wondering how do you know what size injectors i will need.

I'm looking at the ET performance 215cc heads and the AFR 205s. I noticed closet redneck is running 48lbers on his 5.3.

What are the biggest "plug and play" injectors for our trucks?? marine 8.1s??

I would like to stay plug and play, but if I need to, I can re-wire the connectors.

Thanks
-Joshua
I'm in need of the same info. Right now I'm at 98%IDC with just the cam . I'm wanting to go nitrous so adding the walbro and injectors is the next step. I've heard the 8.1's are good, but would like to hear from someone with experience with running the 8.1's

Jake
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Old Jan 30, 2008 | 10:08 PM
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48's are too big..im running 28s on my 6.0..ive also raised my fuel pressure
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Old Jan 30, 2008 | 10:09 PM
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The 8.1 Marine injectors will take you as far as the 5.3 will go n/a. I will have a set available in a couple of weeks.
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Old Jan 31, 2008 | 07:23 AM
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I was thinking the stock 8.1s would be a little too small for how good either of these heads I'm looking at are. Are there any around a 36ish size that are plug and play?

Aren't the 8.1 marine injectors 42lbs??
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Old Jan 31, 2008 | 07:50 AM
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Originally Posted by joshua022
I was thinking the stock 8.1s would be a little too small for how good either of these heads I'm looking at are. Are there any around a 36ish size that are plug and play?
Stock 8.1 are ~31#, I believe the flex fuel injectors are ~36#

Originally Posted by joshua022
Aren't the 8.1 marine injectors 42lbs??
Yes and they are also plug and play.
All require a little adjustment in the tune of course.
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Old Jan 31, 2008 | 11:02 AM
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Default Injector size question

The 8.1 injectors (delphi marine) are 42 #. I am running those in my 5.3 with Whipple supercharger, LS6 cam and Edelbrock CNC heads. Weren't plug and play though, had to put a re-tune on to compensate. Just a bit too rich....
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Old Jan 31, 2008 | 11:06 AM
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Originally Posted by joshua022
I was thinking the stock 8.1s would be a little too small for how good either of these heads I'm looking at are. Are there any around a 36ish size that are plug and play?

Aren't the 8.1 marine injectors 42lbs??
im on the smaller 8.1's. 5.7 liter heads and cam with full bolt ons. im sitting at 96% duty cycle. the small 8.1's should handle the 5.3 perfect
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Old Jan 31, 2008 | 11:28 AM
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Originally Posted by TXsilverado
im on the smaller 8.1's. 5.7 liter heads and cam with full bolt ons. im sitting at 96% duty cycle. the small 8.1's should handle the 5.3 perfect
Even with the really good flowing heads??the lil 8.1s will be enough??

I wish I wouldn't have just sold my set of the little 8.1s then.
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Old Jan 31, 2008 | 11:31 AM
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Originally Posted by joshua022
Even with the really good flowing heads??the lil 8.1s will be enough??

I wish I wouldn't have just sold my set of the little 8.1s then.
i would think so. im on patriot stage 2 ls6 heads with a 226 cam and more cubes and the smaller 8.1 are holding strong.
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