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Discussion Starter · #1 ·
What is the most practicle drive train combo in a CJ7 to be a daily driver, run 80 on the highway, run moab, rubicon, tellico, midwest mud, normal rocky trails every weakend, be cost effective(aka not break the bank), and durable. Engine options are 231 buick v6 (that I have) with edelbrock performer package, carbed chevy350, and tbi 350. Tranny will be a NV4500. The axles will be full width so which ones would be best. Dana 44f, 44r, 60f, 60r, 14bolt r, 2.5tonf, or 2.5tonr. Finally which tires size 35", 38", or 44". Any thoughts, comments, suggestions would be appreciated. Thanks.

Tim Springer
1980 CJ7
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Discussion Starter · #2 ·
Personally, I would use the V8 with bigger tires. 44 front, 60 rear, somewhere 35-38 tires, you didn't say what t-case, but if you are really planning on running 80 on the hwy, think about one such as a 300 that has a crawler gear kit available so you can use diff gears you can live with at 80 mph.

Brad
Get active or get locked out, the choice is yours.
 
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Discussion Starter · #3 ·
Sorry about forgetting the t-case. I have a Dana 20 right now. I was thinking about keeping it to keep costs down. It could get a crawler gear kit if it is warrented. Unless a different t-case is cheaper. The other thing is I would like to get good gas mileage. More ideas and thoughts please. thanks

Tim Springer
1980 CJ7
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Discussion Starter · #4 ·
I would definitly say that a fuel injected engine is the best way to go. Carbs can be set up to work well, but EFI still works best. My vote would be for a V-8 but I'm a small block Chevy (and big block Mopar) fanatic, others could have more info on other options like the Buick V-6. Since you want to run the ENVY 4500 (who doesn't) the overdrive will add a lot of street/highway ability. This can help overcome low diff gearing needed for the trails. If you want to run 80 mph I would stay away from 40's or 44's. Even 38's can have a mind of their own at high speed. I ran 38's on a full size Ford, and their street manners were pretty decent, but a friend of mine with 44's on a Blazer worked for every mile.

To sum up my opinions for what they are worth I would go for a 350 TPI, NV 4500, D-300 w stock gears, a Dana 44 or 60 front preferrably reverse cut, a Dana 60 or Corp. 14 bolt rear standard cut, 4.88 gears (for streetability), and 36-38 inch tires. Course, it is your Jeep and only you can make the best decisions on how to build it.

"My other car is a BULLDOZER"
 
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Discussion Starter · #5 ·
Does anyone know if there is an EFI for the Buick V-6? What about lockers? Any more info will help.

Tim Springer
1980 CJ7
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Discussion Starter · #6 ·
Hey Tim,
Got my locker in the 14 bolt yesterday and put the rearend under the jeep this afternoon. I jacked it up to check the drop weight on the springs without the spring pack clamps on. It did pretty well so I don't think the weight is going to be that much of a problem with the 14 bolt. Now, on to the locker for the 60 front and drop the TF-727 in and I'm off to the rocks for a test drive.

Peanut

 
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Discussion Starter · #7 ·
Let me know when you finish and how it works. Which Jeep are you putting these under. I presume you are running a 360 V-8. I'm still trying to figure out the best setup. Thanks.

Tim Springer
1980 CJ7
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I ran some numbers at http://www.off-road.com/chevy/calc.html for you. Here's what I came up with: A smallblock Chevy want's to run 1800-2800 rpm (Randy's R&P)

35" tires: 2500 rpm @ 4.09 = 85 mph
............2800 rpm @ 4.56 = 85 mph
............2800 rpm @ 4.88 = 80 mph
............2800 rpm @ 5.38 = 72 mph

38" tires: 2200 rpm @ 4.09 = 81 mph
............2500 rpm @ 4.56 = 83 mph
............2800 rpm @ 4.88 = 86 mph
............2800 rpm @ 5.38 = 79 mph

I would use the injected 350, without a doubt (you lucky dog!). I didn't figure 44's cause they're monsterous and really don't belong on the highway, nothin' but trouble on a jeep. Incidentally, anyone see the CJ-5 in March JPMagazine, under the show section, with 44's? How could you ever hope to control something like that on the road? I am always interested in overkill, so I like the 2.5 ton axles, but only if I can buy them from you cheap /wwwthreads_images/icons/smile.gif. Therefore, since you'll need another set, I'd recommend the 14 bolt rear (or maybe 60, but not the 44 with 38's) and the 60 front, reverse cut of course. I am assuming (incorrectly?) that the 80 mph you'll want to do is not long term? If that is the case, I'd go with the 38's and 5.38 gears. You'll want to go as low as possible off road but still retain the on road characteristics. And the 80 mph, in a jeep with 38's is MUCH MORE than I'd want to do, maybe 70 at the top end. 80 in the TJ is easy, but with a crosswind even that's too much.

JEEPN
'81 CJ-8 Scrambled!
GM151/SM465/NP205 twinstick/7" Lift/33" Swampers/D44's F&R 4.10's & Lockrights
 
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Discussion Starter · #9 ·
I don't know if there is EFI for the buick V-6, but it seems to me if you are considering a V-6, I'd consider the Chevy 4.3L Vortec V-6, with Central Point Injection. It will not be any less expensive then a V-8, or not much less, (I am swapping in a Vortec V-6 now) so cost on the engine shouldn't be much of a decision factor.

Jim O'Brien
[email protected]
My jeep page
 
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Discussion Starter · #10 ·
The reason I'm considering the V-6 is b/c I have it in the Jeep already and I was looking to save a few bucks. I know I can but the V-6 up cheaper than buying either of the V-8. Do you think 200-220 lb/ft of tourque is enough to push Dana 44's with 35's or even Dana 60's with 38's. Thanks for the gearing numbers. I like the sounds of the 4.10 and 4.88's for long highway drives. I guess I'm trying to save money without losing too much performance.

Tim Springer
1980 CJ7
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Discussion Starter · #11 ·
I'd go for the 44/60 setup (or even a 44/44 setup with a V6) & preferably the TBI 350. But, since the 6 is already in there, you can make due. The absolute wildest tire I'd even consider for a pavement pounder would be the 38X12.50 TSL & that's really pushing it. 35-36" radials would probably be way better. For the best combo of Midwest mud & road, I'd go for either 36X12.50 TSL radials or 315/75R Radial Buckshot Mudders (Q78). May not be your best bet on the rocks, though.

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 

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I cannot imagine any suspension capable of properly articulating a 44" tire, on a short wheelbase Jeep, going 80 miles per hour on a highway. For a good all purpose Jeep, and around town, daily driver, highway machine, I can't see going over 35's - 36s. The big tires would be tough to balance at the huges sizes, which would be important on the highway, and the Jeep would be so tall I wouldn't think it'd be all that fun to drive for long distances. I don't quite understand how these super-tall show Jeeps can wheel anyway, they're so narrow, and so tall they couldn't stand off camber at all without toppling over on their side. How do you plan to stuff 44s under a short jeep? SOA, with lift springs, and a 4" body lift like one of those magazine show Jeeps? Yikes. /wwwthreads_images/icons/crazy.gif

To build a suspension that will give full articulation and perform well, and still have something that is not a handful to drive, I'd stick with 35s. Get some good axles, as you mentioned, ARBs for no adverse conditions on the street, or Full detroits if you can live with the quirks and want a simple locker, a 350, FI, or carb if you want simplicity, and you should have a nice all-purpose Jeep that won't break.

I am trying to build my Jeep for all-purposes too. I have 33 BFG MTs for off-road, ATs (31s right now, 33s hopefully someday) for the street, and 70 is plenty fast enough on the highway for me.

Just my opinion,
Good luck with your project,
Pete

88YJ,4"susp,33"BFGMT,9kwinch,homemade swingout,258,999,4.10,weber32/36,GMHEI,one moonguy/wwwthreads_images/icons/smile.gif
 
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Discussion Starter · #13 ·
The axles I have already decided are going to be full width truck axles. I'll deal with the tires sticking a mile out from under the fenders. IF I go with 44" tires, which I probably will not due b/c of all the previous advice, I would do a spring over and chop the h*ll out of the fenders. IF I use my V-6 I will build a custom coil spring front suspension. If I go with the V-8 I'll probably have to stick with leaves. So the final question is down to will a V-6 that is lightly built, that I have, turn the Dana 44's or 60's with 35's or 38's or should I go with the V-8 that will cost more and suck more gas but give more power.

Tim Springer
1980 CJ7
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Discussion Starter · #14 ·
I've got a couple of thoughts for ya on this one. First, the V6 is already there. Build for the 8, but drive the 6. You can change the motor late if you want. Do your axles & suspension now & worry about tranny & motor later. That way, if the 6 ain't enough, you can do the tranny swap at the same time as the V8 swap. The only thing you potentially lose is driveshafts. Or, go ahead with the NV4500 now, but still keep the 6. You'll have plenty of power for the road & rocks. The only place the 6 will hurt you is in really deep, sticky stuff. Then, you'd probably be wishing for a 350. 'Course, if you had a 350, you might be wishing for a big-block. At any rate, you won't be able to spin the tires at 40MPH in sticky mud, but you will be able to spin 'em enough to have them self-clean. The Buick engine has a host of aftermarket help available & if you get crazy, you can switch to one from a late-model Camaro or Firebird complete with port injection. Or, add a blower. To help with marginal power, stick to narrow tires & lightweight aluminum rims. Narrow tires work better in Midwestern mud anyway & they're a lot easier to spin due to the reduced weight.

To help with the width issue, I'd suggest a set of 16" rims with very deep backspacing (like stock GM 1/2 tons have these days) & a 7-8" width. Such rims combined with the narrow tires will keep your rig from looking like an overgrown Tonka toy. This will also greatly improve the straight-line stability of your short-wheelbase CJ at highway speeds, reducing the rearend's tendancy to try to pass the front as the road gets a little rough (like it will there between Denver & Burlington). To save some $$$, you could use factory leftover 16" rims that got traded in on some fancier ones. You can get the kind of backspacing I mention out of 5 on 5.5" (late Dodge), 6 on 5.5" ('88 & up GM 1/2 ton), or 8 on 6.5" (late Dodge, GM, or pre '99 Ford) rims.

Just some more stuff to mull over for ya.

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 
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Discussion Starter · #15 ·
Thanks Tex. It would be nice to keep the V-6 to save money. Few more questions just to clear things up. Did the Camaro and Firebird have fuel injection that will fit? Why 16 inch wheels instead 15? Will keeping the axle width down help inprove tracking? Finally do you think it should be a Dana 44 front and Dana 60 or Dana 44 rear? I think I almost have it figured out.

Tim Springer
1980 CJ7
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Discussion Starter · #16 ·
Late model Camaro's & Firbirds (as well as a whole host of GM front-drivers) have port-injected 3.8's (aka 3800 V-6). Adapting this system to your block with potentially different valve sizes, compression, cam, etc. could prove challenging. I couldn't tell you what all would need to be done for that, but if you could make it work, you could also adapt a factory supercharger from a late-model Buick Regal, Pontiac Grand Prix or a couple of others. Could be all sorts of headaches here, though.

As to the axles, I'd personally go with a 44 front & 44 rear if you plan to definitely keep the V-6. With the V-8, the 44 will be fine as long as "extreme rock crawling" isn't in you plans. Then, I'd go for the 60 rear. But, with the 6, breakage of the 44 rear is less likely & it'd be a lot less weight to drag around than a 60.

The 16" rims were suggested mainly because they can be had cheaply (if getting stockers) & also because of the deep backspacing which would narrow the track. If you were to run a leftover set of factory pickup rims with 35-36" rubber, you'd track down the highway in the same groove as a late-model pickup truck. Narrow tires will definitely track better than wide ones - especially if it's wet.

Also, we've found in racing that extremely wide vehicles that also have a short wheelbase have a tendancy to go sideways REAL easy (this will be less of a problem on the highway). Width does help your stability once you get crooked, but being narrow helps to keep you straight in the first place. Sort of a double-edged sword here. But, what we've really found is that track width needs to be in proportion to wheelbase. A full-size longbed pickup need not have axles as narrow as what's on a Jeep to stay straight. But, putting those full-sizers on a 93" CJ can make it almost as wide as it is long. That's really wider than you'd need on the trail, so that's why I'd suggest trying to compensate somewhat with the narrow tires/rims & the deep backspacing. Also, you won't have quite the "fender flare" problem this way. You'll also catch a lot less attention from the law with a more "reserved" appearance.

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 
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Discussion Starter · #17 ·
Thankyou very much. Now I know what is the best (or at least seems to be the best) modifications for my money. Now it is a matter of getting the parts and letting the weather warm up. I guess I don't need to build a Jeep that is overkill. I just need to build a vehicle that will go anywhere with senseable driving. Thanks again.

Tim Springer
1980 CJ7
WALSTIB/wwwthreads_images/icons/wink.gif
 
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Discussion Starter · #18 ·
Well, I surely don't want to talk you out of something you really want. It's just that in all of my previous buildups, the reality of dollars and sense crept in. So, I tend to dish out advice in a similar manner. But, ultimately you're the one who'll own the Jeep & drive it. So, make sure it's wild enough to put a smile on your face /wwwthreads_images/icons/smile.gif.

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 
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Discussion Starter · #19 ·
I can't have what I really want. It would be too expensive too big too much of everything. It probably wouldn't even fit on most trails, but that build up is just another crazy idea. This buildup that I have been asking about needs to be practicle and cost effective. Dollars and sense and cents do matter. I finally had to decide what I really need and don't need and the big thing that I don't need was an empty wallet. Compared to what I have this will be a little wild. Also it doesn't matter how wild the Jeep. What matters is how good the driver is. Now I have to get really good at driving. Thanks for the advice.

Tim Springer
1980 CJ7
WALSTIB/wwwthreads_images/icons/wink.gif
 
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Discussion Starter · #20 ·
I think you've made a wise choice Tim. You could spend every dime you can get and look really cool on a magazine cover a few years from now when it is finally finished, but I'd much rather have something that is fun to drive now (or at the very least ASAP). Besides if you ever decide you really want those 2-1/2 ton axles, Boyce will probably still be there.

"My other car is a BULLDOZER"
 
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