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Just bought an '81 scrambler with the 258 I6, T4, and Dana 300. My plan is to swap in a 360 V8 with the standard upgrades (mild cam, aluminum heads, electronic ignition, etc.). I'll mate that to an AX15 5-spd while keeping the stock Dana 300.

I realize I'll need various adapters from Novak to make it all work but does anyone see any major issues with this setup? This is not a daily driver nor am I a rock crawler. This will be mostly street and trail. Will it hold up?
 

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Just bought an '81 scrambler with the 258 I6, T4, and Dana 300. My plan is to swap in a 360 V8 with the standard upgrades (mild cam, aluminum heads, electronic ignition, etc.). I'll mate that to an AX15 5-spd while keeping the stock Dana 300.

I realize I'll need various adapters from Novak to make it all work but does anyone see any major issues with this setup? This is not a daily driver nor am I a rock crawler. This will be mostly street and trail. Will it hold up?
What is your budget a (serious question) and how much time do you have to get it done?

What are your fab skills like? Do you have a welder?

Are you dead set on having a manual?

How big of a tire do you want to run?

How hard on the skinny pedal are you? Be honest.
 

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Discussion Starter #3
What is your budget a (serious question) and how much time do you have to get it done?

What are your fab skills like? Do you have a welder?

Are you dead set on having a manual?

How big of a tire do you want to run?

How hard on the skinny pedal are you? Be honest.
Good questions!

1. I have about $12K set aside for the engine and tranny.
2. Yes
3. No bigger than 32s
4. Hard. This will be on the street 95% of the time and I want it to be able to roast my tires.

Hope that helps.
 

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Good questions!

1. I have about $12K set aside for the engine and tranny.
2. Yes
3. No bigger than 32s
4. Hard. This will be on the street 95% of the time and I want it to be able to roast my tires.

Hope that helps.
Well I was in a similar boat as you. I have a 77 CJ7. It had a 304AMC with a TH350 and a dana 300 with an AMC20 rear end and a Dana 30 up front. I wanted big horsepower and im hard on the skinny pedal.

So I decided to put a 360 or 390 (401's are way to expensive) in it because bigger is better. Then I needed a bigger radiator to cool the jeep. Then I needed a stronger rear end. Then I needed a manual because I don't like autos. Then I learned it would be cheaper to to just use a chevy drivetrain instead of trying to make an expensive AMC one work.

Do you see where I am going with this? You are standing at the edge of a cliff and wondering if you want to jump off. Your radiator will NOT work. That AMC20 rear end is stronger than a dana 35. But it will not stand up to too much tire roasting. So you might want to look at a 9 inch or JK dana 44, which means you might want to change your front axle as well because your bolt patterns would be different anyway.

And it just snowballs from there.

I am going to let you in on a little secret. If you click the thread below this one... It's mine. I am probably around 15k into my rig and only halfway done and I get a free engine from my uncle because he owns a shop. I did put full width axles under my rig (that i got for $600), I did buy coilovers (which were the most expensive part), and I did build a frame (this only cost me time and $200 worth of steel). The other 12k was all from misc shit.

Putting a new transmission in your jeep and a 360 means that you will have to fab or buy new motor and tranny mounts. You will have to buy/build a new exhaust system or pay someone to do it. Your frame should be fine but check it for cracks and rust. You will most likely have to have custom drive shafts made because your drive train will be a different length since you are using a different transmission and adapting it to a dana300. You should probably switch over to a hydraulic clutch while you are at it.

$12k is a good chunk of change but it can go fast. If I were you... I'd find a junkyard LS and swap it in, 360's are cool but LS's are cooler. You can get 6.0s for around $1,000 if you are patient and you will have fuel injection. You NEED to price everything out before you start. Think of everything I listed and then some more because there is a whole lot more than you think. Come up with a number and then double it. This is what it will cost you.

I hope this helps.

Edit: for what its worth I wish I kept my jeep stock. Its going to be cool when its done but this thing has become such a headache and I just want to drive it.

I did a frame swap for a fellow on this forum last week in three days and I can't even get my shit finished. I busted my ass and thrashed on the thing and it took an extra day longer than I expected. But the kicker is that I can't finish my shit. I just sit in the garage and drink bear and look at it.

Trust me, what you want to do is no easy task. And one thing leads to another in this world of jeeping.

Good luck
 

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Discussion Starter #5
Well I was in a similar boat as you. I have a 77 CJ7. It had a 304AMC with a TH350 and a dana 300 with an AMC20 rear end and a Dana 30 up front. I wanted big horsepower and im hard on the skinny pedal.

So I decided to put a 360 or 390 (401's are way to expensive) in it because bigger is better. Then I needed a bigger radiator to cool the jeep. Then I needed a stronger rear end. Then I needed a manual because I don't like autos. Then I learned it would be cheaper to to just use a chevy drivetrain instead of trying to make an expensive AMC one work.

Do you see where I am going with this? You are standing at the edge of a cliff and wondering if you want to jump off. Your radiator will NOT work. That AMC20 rear end is stronger than a dana 35. But it will not stand up to too much tire roasting. So you might want to look at a 9 inch or JK dana 44, which means you might want to change your front axle as well because your bolt patterns would be different anyway.

And it just snowballs from there.

I am going to let you in on a little secret. If you click the thread below this one... It's mine. I am probably around 15k into my rig and only halfway done and I get a free engine from my uncle because he owns a shop. I did put full width axles under my rig (that i got for $600), I did buy coilovers (which were the most expensive part), and I did build a frame (this only cost me time and $200 worth of steel). The other 12k was all from misc shit.

Putting a new transmission in your jeep and a 360 means that you will have to fab or buy new motor and tranny mounts. You will have to buy/build a new exhaust system or pay someone to do it. Your frame should be fine but check it for cracks and rust. You will most likely have to have custom drive shafts made because your drive train will be a different length since you are using a different transmission and adapting it to a dana300. You should probably switch over to a hydraulic clutch while you are at it.

$12k is a good chunk of change but it can go fast. If I were you... I'd find a junkyard LS and swap it in, 360's are cool but LS's are cooler. You can get 6.0s for around $1,000 if you are patient and you will have fuel injection. You NEED to price everything out before you start. Think of everything I listed and then some more because there is a whole lot more than you think. Come up with a number and then double it. This is what it will cost you.

I hope this helps.

Edit: for what its worth I wish I kept my jeep stock. Its going to be cool when its done but this thing has become such a headache and I just want to drive it.

I did a frame swap for a fellow on this forum last week in three days and I can't even get my shit finished. I busted my ass and thrashed on the thing and it took an extra day longer than I expected. But the kicker is that I can't finish my shit. I just sit in the garage and drink bear and look at it.

Trust me, what you want to do is no easy task. And one thing leads to another in this world of jeeping.

Good luck
whoa! I thought the axles could handle 300 HP. I tryuly don't want to go bogger than that. Maybe a SBC is better in the end.
 

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whoa! I thought the axles could handle 300 HP. I tryuly don't want to go bogger than that. Maybe a SBC is better in the end.
The 10 extra cubes won't really make a difference. If anything you will make more power with your SBC with aluminum heads because you will get much more flow from them opposed to the stock smog 360 heads. And I don't know if anyone makes aluminum 360 heads that can match the price of SBC heads.

Your other option is to upgrade to a one piece axle shafts for your AMC20. I forget who makes them but they are stronger over the stock ones.

A mild engine build at bare minimum should also put out 1.0hp per cubic inch. Higher performance naturally aspirated street engines may get up to 1.25 to 1.35. but you should have no trouble hitting 350HP with a small block.

There is allot that goes into planning this stuff so ask away.

Edit: edlebrock makes some nice AMC heads for a 360 but you could buy some sick dart heads for a SBC for the same price. AMC engine parts will always be more expensive than SBC parts
 

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You da man. Back to the planning stages.
Here is what I would do if I were in your shoes with 12k. Keep you Jeep leaf sprung and see if you can score some 07+ dana 44 jeep Axles for like $600. They will have the same gears and be significantly stronger over your AMC20 and Dana 30. To give you some perspective, I purchased my 14bolt and Dana 60 1 ton axles for $600. I just had to be patient and wait for someone to come down and sell them at a reasonable price.

The front axle will have a drivers side drop on the transfer case but that isnt a problem because you want to change out your t-case anyway. Since you are running leaf springs you shouldnt have any problems making them fit but you will have to grind off all the mounts and weld on some leaf pads and shock mounts. Make sure you weld the leaf pads on so the the axle is mounted under the leaf and not over it. This will give you room to bump up to 35's if you want to.

The axle gears will be pretty high but hopefully you can score some with some lower gears. I wouldn't recommend buying a set of axles with 3.07 gears but if you get them cheap enough its worth it. Besides with a healthy V8 under the hood you will have enough power.

After this you need to start looking at what you want for a power plant and honestly you can go pretty much in any direction here. I would tend to lean towards a small block though. You don't need the power of a big block and all you will do it break shit. 3rd gen hemis out of a 5.7 dodge have like 350 stock and they can be had really cheap now a days. A 350ci SBC is a great option. A ford drivetrain is also a great option because it will come with a transfer case with a driverside drop that will work with your JK axles. Your options here are pretty much unlimited an LS is always a good option too.

Since its a scrambler too and has a longer wheelbase you can even fit a NV4500 tranny in there buy they are NOT cheap. They are strong but not as strong as everyone cracks them up to be.

Once you buy your drivetrain and axles you can buy your radiator and start stuffing it all in there. Mount your drivetrain first then your JK axles. Do this because you want to make sure you weld your spring perches on correctly so that you get a good pinion angle. You want them to be parallel to each other.

Wire the bitch up and order your new driveshafts. You are probably going to want a new brake master cylinder and you may run into steering issues but thats park of the process of putting different axles in the jeep. You will most likely need new brake lines and there is a ton of misc shit to do that I can't think of off the top of my head.

But like I said 12k goes real fast! So when you start to do this do it slow and take your time finding parts. It will most likely take you months to find the right deal on something but if you are looking to do this on some sort of a budget its worth it. Do not however buy shitty crappy parts. Just because its a good deal doesnt mean its good. It will most likely take you at least a year to accumulate half the parts you need if you do it this way.

or.... you could keep that scrambler stock and drive around and enjoy it.
 

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Yeah..... what he said.

As cool as it is to be unique... with your 360 and stuff.... there is a reason that everyone puts in Chevy engines. They are simply cheaper and easier. As an added bonus they are easy to make big power with. All of Tyler's advice is spot on. My build followed a similar path and is linked below if you care to read.
 
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