I was thnking of purchasing a 74 cj5 that is about 75% restored according to the owner. My questions are this, is it possible or should I say within a reasonable budget to switch the 304 motor to a six cylinder? And also, where is good place to get a hard top or do they make a hard top for this model? I new to the Jeep community. Thanks in advance.
74 CJ5 Engine Switch
- Thread starter Langylang
- Start date
Saddle Tramp
New member
To switch out the AMC 304 to an AMC 258 would be fairly simple. You would need to relocate the passenger side motor mount but the bell housings between the two motors are interchangeable and everything will bolt right up with no adaptors required. If you wish to upgrade to a fuel injected 4.0 things get a little more complicated as you will need to get the computer from the donor vehicle, redo some wiring (kits are available for this), and add a few sensors, but of course it cost more money.
Why get rid of the 304? Most guys look to go the other way and swap out the I6. I know the I6s are one of the best motors ever made for a jeep but why not just drop in an AMC 360 and save the money for other goodies; they are plentiful and cheap.
There was a factory made after market steel hardtop available for your year of CJ. You may have seen them around, they look like a square box. There are also fiberglass tops available too. Prices vary but I have seen the steel tops go for as little as $300 when a seller does not know what they have and new fiberglass tops are over $2,000. Used prices I have seen generally range from $700 to $1,200 +/-, but it rains a lot where I live so they may go for more money.
The last thing I would like to say is a personal opinion. Keep your Jeep, Jeep. Leave the Chevy and Ford V8s where they are, in Chevys and Fords. I know Jeep begged, borrowed, and stole parts from everyone they could over the years but I think to use parts that were put in a Jeep at one time is best.
PS: Try Craigs List under Auto Parts for used tops. Hardtops are hard to find so it may take a while to come up with one.
Why get rid of the 304? Most guys look to go the other way and swap out the I6. I know the I6s are one of the best motors ever made for a jeep but why not just drop in an AMC 360 and save the money for other goodies; they are plentiful and cheap.
There was a factory made after market steel hardtop available for your year of CJ. You may have seen them around, they look like a square box. There are also fiberglass tops available too. Prices vary but I have seen the steel tops go for as little as $300 when a seller does not know what they have and new fiberglass tops are over $2,000. Used prices I have seen generally range from $700 to $1,200 +/-, but it rains a lot where I live so they may go for more money.
The last thing I would like to say is a personal opinion. Keep your Jeep, Jeep. Leave the Chevy and Ford V8s where they are, in Chevys and Fords. I know Jeep begged, borrowed, and stole parts from everyone they could over the years but I think to use parts that were put in a Jeep at one time is best.
PS: Try Craigs List under Auto Parts for used tops. Hardtops are hard to find so it may take a while to come up with one.
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I guess the main reason for wanting to swap motors is that I do not plan on doing any hardcore offroading. I was thinking the 304 might be overkill. I just plan on hitting the beach and use it for hunting. Nothing to serious, also, I plan to pretty much use it for a daily driver. Thanks.
Saddle Tramp
New member
I can understand your position. The reality is in 1974 the AMC 304 only has 150 HP while the AMC 258 has 110 HP. Not much difference really but having said that, there are differences between the two motors. In my opinion, the AMC I6 is the best all around motor for a CJ/Wrangler primarily due to the low end torque abilities and potential longevity. You will get better gas mileage over the V8 too.
As I said before the cheapest and easiest way to make the change would be to use a carbureted 258. There can be some issues with carburetors too but this is curable without much cost.
As I said before the cheapest and easiest way to make the change would be to use a carbureted 258. There can be some issues with carburetors too but this is curable without much cost.
I am in the Hampton Roads area of Virginia, in the Southeast corner. I have not purchased anything yet. There are what seems to be several deals in my area and I am not sure on which one to go for. My goal is to do complete tear down and rebuild. The one with a 304, the owner claims it runs. I just figured if I did buy that one and rebuild it, maybe switching to IL6 would be the way to go for mileage. Having said all of that, this would be my first jeep and first tear down and rebuild. So many decisions.
Saddle Tramp
New member
The one thing to remember when it comes to buying jeeps is that the money and time you put into them is purely a labor of love, not an investment. It is very unusual to get much more than ten cents on the dollar invested when you go to resell and sometimes you don't even get that. There are exceptions but generally not the norm. As such, try to find a jeep that has the most "goodies" on it for the dollar in relation to what you want to use the jeep for. As an example if you want to use the jeep around town as a daily driver a CJ with 6" of spring lift, 2" of body lift, and 35" plus tires with deep gears in the pumpkins may not be what you are looking for at any price but one with a mild lift, 32" tires, nice wheels, new seats, sound bar, and a fresh I6 motor may be.
The condition of the body and frame mean a lot so by no means would I eliminate a V8 (as your desire is for an I6) with a great body and frame from the mix just because it had the V8, but if I can find a CJ that already has the right motor and a good body and frame then there is a lot more money to put elsewhere into the project. All these parts cost money!
(Sorry to tell the story again Jon but it is relevant…)
I bought my 1978 CJ5 in 1994 from a guy who had spent $9,000 (remember this was 15 years ago so it would be a lot more in today's money) on the jeep during the last 12 months he owned it. I have all of the receipts so I know what was done. The guy originally paid $3,500 for the jeep, spent the $9,000, and then sold the jeep to me for $3,750. So lets do the math, he spent $9,000 on the jeep and got $250 more for the jeep than he originally paid for it = $8,750 to the bad. Now before you label him the fool of the century you should know he was under pressure from his girlfriend to get rid of the jeep, probably due to the $9K he has just invested, but in 1994 a good CJ didn't go for more than $3,750 in my area; I bought it because of all the "goodies" that were already there and was glad to get it.
Also, try not to get jeep fever if you can; I know it's hard and have had it my self on several occasions. Jeep fever is when you buy a jeep just because you want a jeep fix and you want it now. The side effect of jeep fever usually is an empty wallet from having to redo all the things you overlooked and just didn't allow yourself to see while checking out the jeep. Again, this is from the "been there, done that" department so I know of what I speak. Anyway, to me the hunt is half the fun, whether it be for a jeep or parts.
Good Hunting!
The condition of the body and frame mean a lot so by no means would I eliminate a V8 (as your desire is for an I6) with a great body and frame from the mix just because it had the V8, but if I can find a CJ that already has the right motor and a good body and frame then there is a lot more money to put elsewhere into the project. All these parts cost money!
(Sorry to tell the story again Jon but it is relevant…)
I bought my 1978 CJ5 in 1994 from a guy who had spent $9,000 (remember this was 15 years ago so it would be a lot more in today's money) on the jeep during the last 12 months he owned it. I have all of the receipts so I know what was done. The guy originally paid $3,500 for the jeep, spent the $9,000, and then sold the jeep to me for $3,750. So lets do the math, he spent $9,000 on the jeep and got $250 more for the jeep than he originally paid for it = $8,750 to the bad. Now before you label him the fool of the century you should know he was under pressure from his girlfriend to get rid of the jeep, probably due to the $9K he has just invested, but in 1994 a good CJ didn't go for more than $3,750 in my area; I bought it because of all the "goodies" that were already there and was glad to get it.
Also, try not to get jeep fever if you can; I know it's hard and have had it my self on several occasions. Jeep fever is when you buy a jeep just because you want a jeep fix and you want it now. The side effect of jeep fever usually is an empty wallet from having to redo all the things you overlooked and just didn't allow yourself to see while checking out the jeep. Again, this is from the "been there, done that" department so I know of what I speak. Anyway, to me the hunt is half the fun, whether it be for a jeep or parts.
Good Hunting!
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