Questions on a 72 CJ5 w/ V-8

Hello all,

Its been a long time since I've been on the forum. But alas I'm addicted to Jeeps and since the divorce is final I'm looking to buy another Jeep. I've searched the forums for information but haven't really found what I'm looking for. I found one for sale online but I don't have that much information about it. I know its a 1972 Jeep Cj5 w/ manual trans and V8, guessing 304??? I'm just looking to get some more information about this year CJ. Did it come with disc brakes as an option or were they all drum? Is the V8 good or would it be better off used as a boat anchor? Are there parts to modify the 304? I believe parts from a 360 are interchangeable but I'm not sure. It runs and drives, what would the manual trans be? T-18 etc??? It is bone stock, it has not been modified in any way so any odd concoctions are probably non existant. Also what axles were used? I had an early CJ5, Renegade 1, I was wondering if it was similar to something like that or has it been updated? Is it better than the earlier CJ? I know there was information on this site about my early CJ but for some reason I can't seem to find it again. Thanks again in advance, Talk to you all soon,
Mike AkA littlepurplecj

 

Mike I think all of this is on the ECJ5 tech pages, but briefly
304 V8
T-15 3-speed
Dana 20 TC
Dana 30 open front axle
Dana 44 rear
11" drum brakes, no disks
PS/PB optional
3.73 axle ratio, 4.27 optional

Look on the ECJ5 tech pages or www.jeeptech.com for the specifics on each.

304 is a good engine, same external dimensions as the 360 or 401 but the block, crank, heads, rods, and pistons are different for each.

hth!

 

The 304 responds well to a 4 barrel and headers. They seem to outperform a GM 305.

 

Ok I ended up getting the Jeep off of Ebay for $625. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=120034813887. It has the typical michigan jeep rust issues. I read on the tech page that they changed the frame in 73 to combat frame cracking issues on the 72, what did they change and what can I do to the 72 to stop that? Also how hard is it to find a hard top for one of these? Thanks again guys, the input has been good. What do you think of the edlebrock performer air gap maniflold and a 600cfm edelbrock carb??? Again the 304 is stock, would that be a good idea???

 

I owned a '73 and it still cracked. I had thought the '75s were upgraded, but not certain. Likely they used thicker frame rail material.

The usual cracking is in the frame rails right behind the front crossmember and steering box bracket, DS. Also a lot of stress around the spring mounts. I'd recommend you look at the entire frame closely - cracking is a common problem for all CJ-5s.

 

I was thinking the frame didn't get boxed till 76, but not 100% sure. On my 72, I cut and welded an extension to the boxed area behind the front spring hanger, so that it is boxed about 8" more. I read an article about beefing this area a little to fix the cracking problem TIMGR refers to. I have the Edlebrock intake and truck avenger on my 72 CJ w/304 and I am very happy with it. One thing to keep in mind is that the 304 is no fuel miser and most mods don't help any.

 

Yes, that's right. The boxing causes other problems though (rust).

 

I have 2 more questions, first off, would it be worthwhile to swap in a 360 instead of the 304? or would that be too much for the little cj? also how much of a lift is needed to get 35's to fit? I have a nice set of 35's I want to use, just gotta get them to fit, what lift is recommended, shackle, spring, or body? or all?

 

The 360 is a popular swap; one reason may be availability. 360 remans are easier to get than 304s, and you can pick up rusty Wagoneers with a 360 for very little (though they are usually high mileage). Nothing wrong with the 304 - AMC ran it in their TransAm cars against 302 Mustangs and 305 (?) Camaros, and did very well. Especially in the early 70s, the stock 304 has plenty of power for a CJ IMO. Hop-ups would be way down on my to-do list.

 

Camaros 302s

 

Does anyone have the hp ratings for a 360 from a late 70s cherokee??? I was just curious how much of a gain it had over the 304. I may just put on a performer intake and 4bbl carb and call it a day. Thanks again for all the information,
Mike

 

For '72, there's a 25hp difference between the 2V 304 and the 2V 360. As time goes on, the hp ratings steadily decreased for both engines, although I have no specific data re how much. By the time the 304 was discontinued, the hp difference between it and the 258 was so minimal that offering the 258 and 304 probably was no longer realistic.

Have you driven the car yet? If not, you're really putting the cart before the horse to think about performance upgrades.

 

Just a comment about displacement vs. power: there's no real mystery to this - a larger engine comparably equipped will make more power in proportion to its increase in displacment.

360/304 = 1.18 or 18% larger.

The 304 and 360 made 150 and 175 hp in 1972 resp.

175/150 = 1.17 or 17% more. Pretty close.

There's no replacemnt for displacement, but realize that you only get as much power out as the fuel that you burn. A larger engine has larger capacity for fuel, so it makes more power. Not mysterious.

 

Comparing a 304 and a 258 is rediculous! Again, a 4 barrel and a good exhaust really wakes up a 304, just try to wake up a 258 and see how much success you have. Power is a great asset off-road regardless of what anybody says. A 360 is also a great swap. They seem to be a signficant improvement over a 304. If more power is what you are after, go for it! Horsepower really improves the already great fun-factor of Jeeps!

 

You miss the point. Near the end of it's run (80-81?), the 304 was so choked by smog equipment that its hp and torque had decreased to near the same as the 258. It's hard to sell the 304 for a premium over the 258 when it's only rated a few hp more... the 258 had been significantly upgraded in 1981, with new manifolds, new carburetion (the BBD!) lighter block, and a much lighter crank.

You have to compare stock to stock. It's only now, 25 years later, that some owners have the freedom to remove the strangulating devices, and though the smog laws aren't enforced everywhere, removing devices is still illegal everywhere.

 

My 304 hadn't been started in 12 yrs, the Jeep sitting in weeds. New oil and a new battery...a little hotwiring... and the engine turned over with no apparent problems. That, to me, is the sign of a good reliable engine.

 

That's why I like my 283 engine. (1964 vintage) No smog equipment, not even a pcv valve. It still has the crankcase breather pipe running down over the bellhousing. It's got enough power (even with the 4.88's) to take me any place that I have enough guts to try.

tommy b

 

When I bought my jeep the 304 had been replaced with a completely stock 360, I installed a edelbrock performer cam and intake manifold with a rochester quadrajet carb and headers, wow, that thing really woke up! I enjoy having the power/torque when needed, seems like it is easier to drive something that is overpowered than underpowered. You choose how fast you want to go, not the engine. One thing I will say, if you choose to run a bigger engine hard, your drivetrain might show its weak links! I used to push mine hard, and I found all of the weak links!

 

No, I think you are making my point for me. The factory can do everything possible to bog down a 304 with emission restrictions, etc, and then they try and beef up a 258 straight six, and then, just as you said, the 304 will still have more power. Have you ever seen a 258 try and compete at a mud drag? Anyway, the guy just wants more power for his new jeep. Of course he is going to fix the brakes, lights, wheel bearings, cracked frame, and whatever else first, but there is nothing wrong with looking foward to a good fun performance mod! If I had a 360 ready to drop in, I would. But If I didn't, and had a solid 304, I would be freeing up some horsepower and having a great time!