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Discussion Starter · #1 ·
I got an 89 dodge 1 ton 2wd. In january issue of dieselpower there's a complete article on modifying first gens. in that article they mention that early first gens (89 to 91 1/2) are not intercooled and have the 3 spd auto, not overdrive. But they do have bigger injectors than the later models and the 3.07 axle gears. The later models (91 1/2 to 93) are intercooled and have overdrive transmissions. Figured it would be easy and cheap to find a junk later model and swap in the intercooler and plumming, and the transmission and get a 25+ mpg truck. I looked around and may have found a family friend with an old 92 i think just like mine, but with the intercooler and everything. Any hints advice or more information on the differences between these amazing trucks?
 

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Everything is a direct swap over. Bolt it on and go.
 

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. Figured it would be easy and cheap to find a junk later model and swap in the intercooler and plumming, and the transmission and get a 25+ mpg truck.
What? I don't understand what you wrote.
 

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What? I don't understand what you wrote.
he wants to take the intercooler and tranny out of the 92 and stick it in his 89. if they have bigger injectors would it be worth putting them in a later model like a 93?
 

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Early model injectors will not fit the 91.5-93 years. Larger tips.

The intercooler will hook up but you will need to do some mods on the grill for clearance. Not sure what all needs to be worked on. Do a search on this and see if there are some posts from earlier times that will help.
 

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Discussion Starter · #6 ·
about the 25mpg... Think. the 3 spd uses 3.07 axle gears. the later model overdrive uses a lower gear. You throw the overdrive in with the 3.07 gears you get an extra low engine rpm at highway speeds. and it wouldn't be worth it to put the injectors in a 93 considering i don't have one. mine's an 89 and i don't feel like buying another truck. The 93 i found is in really rough shape sittin in the weeds. and moddifying the grill for the intercooler will not be a problem. I do stuff like that all the time. Weld up brackets and stuff. easy
 

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Discussion Starter · #7 ·
Early model injectors will not fit the 91.5-93 years. Larger tips. QUOTE]

Why not? It's the same block and heads isn't it? As far as i know the motor itself has not changed in those years.
 

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The 89-91.5 have 9mm and 91.5-93 have 7mm tips.
 

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In order to swap injectors you would have to swap heads. The NON I/C heads are prone to cracking also. IMO though id run what you have now and swap the intercooler and tranny. :thumbsup:
 

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Discussion Starter · #10 ·
In order to swap injectors you would have to swap heads. The NON I/C heads are prone to cracking also. IMO though id run what you have now and swap the intercooler and tranny. :thumbsup:
That's what my plan was. It's the non intercooled one with bigger injectors. Don't know why dodge would switch to smaller injectors after putting an intercooler in. Makes no sense, but that is just corporate america i guess. Probably to keep power ratings down or something
 

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That's what my plan was. It's the non intercooled one with bigger injectors. Don't know why dodge would switch to smaller injectors after putting an intercooler in. Makes no sense, but that is just corporate america i guess. Probably to keep power ratings down or something
As stated, the physical threads and heads are smaller on the later ones, because the eariler heads are prone to cracking, because of the larger holes...

Mike
 

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Discussion Starter · #12 ·
I see. I was thinkin it was just a bigger nozzle or something. I'm no expert. only thing i know about diesels are from experience on my truck, a lot of magazines, diesel mechanic friends, and here. But i learn quick and am smart. lol
 

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The overdrive engagement is controlled by the pcm in the later first gens, so youll need to do some wireing as well.

The smaller 7mm injectors on the newer first gens will not respond to pump tweaks like the 9mm ones. obviously, the larger nozzles will flow more fuel, so the 7mm units may reach the upper limits of their flow quicer than youd like.
 

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The 93 i found is in really rough shape sittin in the weeds. and moddifying the grill for the intercooler will not be a problem. I do stuff like that all the time. Weld up brackets and stuff. easy
How's the grill on the parts truck? Why not swap the radiator core support as well as the inner cooler, and radiator. Seems like it might be faster than fabricating brackets and modifying the grille to make everything work. Just a thought.
 

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Discussion Starter · #15 ·
good idea. grill looks really faded and rough shape. probably better to keep mine and tuck it in there. And I plan to keep my bigger 9mm injectors anyways. Don't feel like swapping heads quite yet.
 

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the 2nd gen intercooler is so much better the 1st gen. but you will need adapters or the newer pipes. its a lil more work but its worth it. i gained 10psi and i cant get the egts over 800 f. although i havent got injectors yet.
 

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the 2nd gen intercooler is so much better the 1st gen. but you will need adapters or the newer pipes. its a lil more work but its worth it. i gained 10psi and i cant get the egts over 800 f. although i havent got injectors yet.
You more than likely had a leaky 1st gen intercooler then. Generally, when you go to a bigger, better intercooler you lose boost, not gain it. Boost is a measure of restriction, not flow. Bill Gilbert is making 556rwhp and he is using the stock 1st Gen intercooler.
 

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You more than likely had a leaky 1st gen intercooler then. Generally, when you go to a bigger, better intercooler you lose boost, not gain it. Boost is a measure of restriction, not flow. Bill Gilbert is making 556rwhp and he is using the stock 1st Gen intercooler.
:agree2: why are all these people bragging about boost???? it is like you said restriction! to me thats like bragging about having crabs or some other std. i would rather have 3in ic tubes and bigger intercooler with 10 psi than a stock with 40 psi. just my two cents
 

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Discussion Starter · #19 ·
The more boost the better. That means more pressure in the cylinders before the compression stroke. which means more air and more power. He's kinda right. In order to have boost you need some restriction. Boost is how much more air the turbo is pushing in than the pistons can hold. Kinda like blowing into a balloon that won't stretch.
 

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The more boost the better. That means more pressure in the cylinders before the compression stroke. which means more air and more power. He's kinda right. In order to have boost you need some restriction. Boost is how much more air the turbo is pushing in than the pistons can hold. Kinda like blowing into a balloon that won't stretch.
False. Brian Block made more power at 60psi then he did at 80psi. So you would rather have an H1C pushing 60psi, then a 62/71/14 S300 pushing 40psi?
 
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