Engine swap - repair - OPINIONS NEEDED

City
Charleston
State
SC
#1
My wife ran our 1984 Scrambler hot yesterday and very likely wrecked the engine (to her defense the temperature gauge did not work properly).
The CJ-8 has a 5.0 AMC 304 V8, recently original re-built 3-speed automatic transmission, original metal tub - great rust free condition, fenders, hood and frame are in top condition.
I am debating if I should try to have engine rebuilt, swap engine to a crate-motor... any opinions?! Everything is really nice on this Scrambler except when I open the hood it looks pretty patched & junky, gauges lack control... Part of me would like to have that mess cleaned up properly. I am trying to get a reliable daily driver (my family should be able to use it for school, sports, beach), at the same time I don't want to "mess up a rare Jeep", I would like to spend my $$$ smartly in terms of value and re-sale value... I don't care about hard-core "old-school" restoration since the family should enjoy driving the truck. I think having a bit more "muscle" is tempting to me... Thoughts?!
What brand of crate-engines are desirable? I appreciate any kind of opinion.
Thank you so much for your help.
 

Attachments

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#2
Don't fret over messing up a rare jeep. Scramblers never came with the V8 from the factory, so it had an engine swap previously.

I suggest a rebuild, a SBC swap, or a LS swap. :twocents:
 

walkerhoundvm

Typical Know-it-all
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
#3
Engine rebuild would be the easiest, cheapest, and most straightforward. Probably the fastest, too.

Although I'm doing an LS swap, I have plenty of time. It's proving to be expensive and technically a little challenging.
 

Bugman

The Rubicon, my backyard
City
Pollock Pines
State
CA
#6
I love my Hemi but what everyone else is saying is true. The swap was challenging and costly but to me worth it. I didn't have a deadline and I was commited to spending what was necessary. A rebuild will be much cheaper and you can clean up the engine compartment when the engine is out. As Eric said, EFI will make a world of difference.
 

sdsupilot

CJ-8 Member
CJ-8.com Member
City
OKC
State
OK
#7
Coming from someone who just finished a full swap. If you are/were happy with the performance of the 304 and 3 speed auto - I would rebuild. The current wiring could be cleaned up and loomed in a few hours.

If you want more performance or overdrive an LS is tough to beat, but be honest with the budget.
 

CJeep

Scrambled
LIFETIME
CJ-8.com Member
City
Easton
State
CT
#9
Don't rule out a 4.0. Tons of them out there. Great parts and support. Probably will make more actual power then a 304.
 

TravelnMan

Legacy Registered User
City
Granby
State
CT
#10
If I had to do it over again I would have just put an EFI on my 360. I went the 5.3L swap route and the power is great, but it was a lot of time/expense to do it. I could have easily rebuilt the 360 and put an EFI on it for what I have in engine, trans, adapters, drive shafts, wiring, exhaust etc... it's a long list.
 

93_Fummins

CJ-8 Member
CJ-8.com Member
City
Edmond
State
OK
#11
x2 to what ^TravelnMan said. The "little" stuff involved in a swap is what really kills the time and budget. At the end of the day, an engine is just an air pump; none are really "better" than any others if all else is considered equal. Hotter ignition, better flowing exhaust, reliable EFI system all thrown on to catch up the ol AMC with the times, and it should be very enjoyable, while retaining that hint of "purity".
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#12
At the end of the day, an engine is just an air pump; none are really "better" than any others if all else is considered equal.
In reality, modern engine design is leaps and bounds better than engines of even 10 years ago. Much of that can be contributed to electronics, but there is a lot of better design in the heads, intakes, valve train, etc...

That being said, the 360 has more than enough power for a jeep.
 

Ron84cj

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
West Bend
State
WI
#13
A lot has to do with how much things go for in your area. Good machine shops have different rates depending on area as well as used motors. For example my 5.3 had 86,000 miles on it. It included the starter, harness, computer, and all the accessories for $500. I did my entire swap for about $2000. And that was including the adapter needed to run an ax15. In some areas you couldn't dream about doing it for that amount. But I found cheaper ways than just buying one big expensive conversion kit. By the time you rebuild the 304 and add efi, it could potentially be much more expensive than the ls swap. As far as value goes, I personally really don't think you would hurt the value of the Jeep either way. I really don't think any potential buyer would have any problem with a 5.3 or a well built fuel injected AMC.
 

Bugman

The Rubicon, my backyard
City
Pollock Pines
State
CA
#14
Ron brings up a good point I hadn't thought about. Labor and parts prices DO vary depending on what area you live in. Out here in California you can expect to pay top dollar on everything you touch or even think of.
 

93_Fummins

CJ-8 Member
CJ-8.com Member
City
Edmond
State
OK
#15
In reality, modern engine design is leaps and bounds better than engines of even 10 years ago. Much of that can be contributed to electronics, but there is a lot of better design in the heads, intakes, valve train, etc...

That being said, the 360 has more than enough power for a jeep.
You're not wrong, but "Leaps and bounds" is a stretch in my opinion. Electronics is definitely the biggie, but that's why I suggested hotter spark and EFI for the AMC to catch it up a little. Displacement for displacement, the modern head design and valve changes don't really change overall performance area under the curve; they simply shift the power curve peak to wherever the engine will benefit most. It's not like there weren't great breathers in the olden days, they just weren't as common because the nature of carburation and the desire to generate more peak torque down low in the low revving workhorses. EFI and digital ignition timing just let you run the upgraded heads, compression and cam from the factory, essentially, without having drivability issues. You definitely could have built just as good of a performing engine 10 or even 20 years ago, so design really hasn't improved as a whole, but the computer and the manufacturing efficiencies simply let you get better performing parts from the get-go without having to break the bank with high-zoot aftermarket stuff on the antiquated short block. But I digress...
 

Ron84cj

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
West Bend
State
WI
#16
Just because cylinder heads breathe well doesn't make them good. Cylinder head design ABSOLUTELY makes a huge difference in efficiency. Not just the port size, but the port shape, valve angle, and very importantly the combustion chamber size and shape. Those old cylinder head combustion chambers from the 70s and 80s did absolutely nothing in efficiency. Sure a good efi system will help. But you certainly won't get the same power or mpg as a modern engine without spending serious money on cylinder heads, can, intake, etc. Why do you think the LS engines are so popular? A simple can swap in a little 5.3 will get you over 400 hp. Not trying to be a jerk. But a lot of people expect too much from slapping on an efi kit on an engine designed 50 years ago.
 

bigwalton

Picture cravin' AK Postal nut
Staff member
SOA Member
City
Dexter
State
MI
#17
Doh! I didn't even think about this :headbang: Since you have the 304, if you could find a good runner or a rebuilt 360, throw that in with what you have and either add an EFI kit or run it until you can upgrade to EFI later.

On the old vs. new V8, I don't think anyone here is saying that a 360 with EFI will get you anywhere near an LS, it's just that, in this case with a 304 already in place, the complexity and cost of simply sticking with another AMC V8 and improving how well it starts/runs (NOT that it will boost power) with an EFI is the least painful way to go.

I really don't think anyone is claiming that EFI magically gets you HP or torque, it's just a matter of drivability and simplicity. So the 360/EFI vs LS is a matter of an "80:20" or "good enough" way of looking at things.

I've broken a D44 stub shaft with a 258 (yes I was being stupid, but still) when you toss in 400 HP you start having to worry about a LOT of other things, so while it may be the "cheapest power" option, it's not always the smartest option for everyone and not everyone is simply concerned with power numbers. I think this is where some of the resentment of the "LS swap all the things" mentality comes from. :shrug:

Got to love that there's so many options out there to consider though!
 

walkerhoundvm

Typical Know-it-all
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
#18
I've broken a D44 stub shaft with a 258 (yes I was being stupid, but still) when you toss in 400 HP you start having to worry about a LOT of other things, so while it may be the "cheapest power" option, it's not always the smartest option for everyone and not everyone is simply concerned with power numbers. I think this is where some of the resentment of the "LS swap all the things" mentality comes from. :shrug:
One of the most common things I've read from people who've done an LS - I'm glad I did it, but there's more to it than I expected. That is exactly how I feel. It can be done pretty low budget, sure, but there's a significant amount of work involved, more if you want to save money. And time is money. I might just add everything up at the end and we can have a thread dedicated to costs.
 
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