This is what I am putting in my YJ. I also want it now. To help me do this I was going to use aan AX-15 out of a 97 TJ I have laying around. As long as I take it easy think it will last a year or two untill I can afford the SM 465 tranny.

Umm...I'm pretty sure you'll be replacing that trans sooner than later, and I think you can get an SM 465 or SM420 and t-case adapter cheaper than the Chevy V8 to AX-15 junk that you'll be throwing away when you swap out to a real trans. Spending money is fine, spending money twice to do the same job right the second time is just plain dumb. Think about the SM420 overthe SM465, it's smaller case size and huge bulge on the passenger side works well in a YJ or any driver's side diff application. 425hp is an awful lot of motor for a trail Jeep, and dune blasting or drag racing won't be any fun with any of the truck fourspeeds, think about speed shifting a dump truck, you get the picture, maybe auto trans would be a better route to go with your bling bling race motor, although only 1 out of 100 supposed 400+ horse chevys are really what they are claimed to be, 400 horse is a lot more that most people realize.

what about the nv4500

Originally posted by subs1000w
what about the nv4500

Yeah they keep talking about it in all the mags and on JU

What axles are you running?.......regardless of the tranny you use be it the ax-15 or the 465, if you still go the Dana 30 & 35 the 425hp engine will blow the heck out of those too!
The 465 swap is dirt cheap, sure they are so plentyfull they are almost free...If you can't afford a adapter then just run the 205 t-case which you probally need to stand up to the HP & torque your engine is gonna dish out.

An NV4500 would be a great choice, as a matter of fact, I just found $3000 laying on the sidewalk so that's what I'm going to go buy when I get out of work tonight. I put a SM420 into my Jeep for less than $800, including the trans, rebuild, adapter ($600 alone) clutch, hydralics, the whole shiz-bang, I couldn't get the billet shifter knob for an NV4500 for that. The NV4500 is great for a bling bling Jeep, my Jeep doesn't even rate a blin.

Gotta have that 5th gear for the highway :flipoff2:

For me to do the AX-15 I will be out 417 bucks for the adapterplate which I could hopefully resell for 200. To do the NV4500 it will cost arounf 3,000 to 3,500. To do the SM465 in the neighborhood of 2,000 that includes a 800 dollor fresh rebuilt tranny. I heard the AX-15 does good behind V-8 and If I treat it nice then it should last a long time. I do not plan on dumping the clutch or power shifting.

Originally posted by Doc Johnson
I do not plan on dumping the clutch or power shifting.

So you won't be wheeling the Jeep or accelerating very fast:flipoff2:

Originally posted by Doc Johnson
To do the SM465 in the neighborhood of 2,000 that includes a 800 dollor fresh rebuilt tranny.

Are you using a gold plated SM465? Shouldn't pay more than $100 for one that will bolt right up to your 355, crazy stuff.

Originally posted by LAME


Are you using a gold plated SM465? Shouldn't pay more than $100 for one that will bolt right up to your 355, crazy stuff.

I have to deal with the inflated prices in IN. The cheapest junk yard one cost 350 bucks then I had to buy the bellhousing for another 75. If you can get one for 100 I will buy it off you for 150. :mad:

Originally posted by bigdude


So you won't be wheeling the Jeep or accelerating very fast:flipoff2:

:flipoff2: There is no need to dump a clutch or do burnouts in a Jeep. That is what my vette is for!! :flipoff2:

Originally posted by Doc Johnson


I have to deal with the inflated prices in IN. The cheapest junk yard one cost 350 bucks then I had to buy the bellhousing for another 75. If you can get one for 100 I will buy it off you for 150. :mad:

It might be worth your while to Run up to WI or MN and dig through some pick and pulls. Lots of axles, motors, tranny's..etc...all the trucks get cancer and dies pretty quick, so there are lots of parts around.

Dude, as soon as you pulled outta the driveway, your AX-15 would explode. :rolleyes:

You don't need a brand New NV4500. When I swapped in the Ramjet, I got mine (1992 Chevy 6.34:1 1st gear) used from a yard for like, $900. The bellhousing was another $100. So they're not as expensive as everyone thinks.

Check Carparts.com. I checked AFTER buying mine and they were selling for around $700-$900 on average.

AT LEAST pony up for the SM465. Why would you wanna skimp on the transmission when you're putting such a powerful engine in there...?

HTH
Jake

All right already. I will put off the project untill I can afford a good tranny. All my money is going into the engine. Anyway for those of you who know does the SM465 shift like the NV4500. I have driven a NV4500 and it shifts fine to me. The jeep is not my daily driver so fifth gear is not needed. I guess I could get a rebuilt SM 465.

Yeah, screw adapting to that AX-15.
Just shell out the jack and do the SM 465.
You still have the stock T/C? depending on the year of your YJ either a 231 or 207, neither of those will hold up to that kind of power.
Then your onto the axles............
I'm being patient, (not really) I have a 5.0 HO thats ready to go in,
RC D60's with detroits ready, NP 435 ready, just waiting on my 203/205 doubler.
It only takes 1 time to make a stupid mistake with a motor like that and you'll be replacing the part or parts next to it.

Originally posted by doctor_G
Yeah, screw adapting to that AX-15.
Just shell out the jack and do the SM 465.
You still have the stock T/C? depending on the year of your YJ either a 231 or 207, neither of those will hold up to that kind of power.
Then your onto the axles............
I'm being patient, (not really) I have a 5.0 HO thats ready to go in,
RC D60's with detroits ready, NP 435 ready, just waiting on my 203/205 doubler.
It only takes 1 time to make a stupid mistake with a motor like that and you'll be replacing the part or parts next to it.

I know I will need a ford 8.8 or Dana 60 rear but My buddy has a LT1 with a Dana 35 and has been lucky so far.

Originally posted by Doc Johnson


I know I will need a ford 8.8 or Dana 60 rear but My buddy has a LT1 with a Dana 35 and has been lucky so far.

Wha does the LT1/D35 Just sit on the driveway? :flipoff2:

Originally posted by Wish4YJ


Wha does the LT1/D35 Just sit on the driveway? :flipoff2:

He wheels it. He actually went rock crawlin at the bad lands a couple of weeks ago. :flipoff2:

"does the SM465 shift like the NV4500?"

Bahwahahahahahahahahahahahahahahahaha!

Does a Dumptruck shift like your Vette? Think School bus, or Bread Truck, or.....Zambonie, no, I'm sure those are auto's, anyway, there's just no comparison. Plan on gear whine and loud clunky shifting with a long throw, the average drwbacks of any real heavy duty truck manual trans

Originally posted by 4Bangler
"does the SM465 shift like the NV4500?"

Bahwahahahahahahahahahahahahahahahaha!

Does a Dumptruck shift like your Vette? Think School bus, or Bread Truck, or.....Zambonie, no, I'm sure those are auto's, anyway, there's just no comparison. Plan on gear whine and loud clunky shifting with a long throw, the average drwbacks of any real heavy duty truck manual trans

Well the NV4500 is supposed to be a heavy duty tranny. :eek:

Yeah, and the new HD and Super Duty pickups are supposed to be heavy duty, but you can't put a plow on half of them. The trans shop that I sneak in to work on my junk at night rebuilds broken NV4500's about once every six months, They've been in business for over thirty years to this date they have only rebuilt a hand full SM465's, and that was mostly swap jobs where the owner wanted the trans freshened up with new seals, bearings, etc. There's only about six gajillion SM465's out there, and many of them have been running in 1-ton plus capacity trucks for better than 20 years.

think about speed shifting a dump truck

I've got this exact sitiation:( I'm running a built 383 LT-4. balanced, buleprinted, ported, 11:1 compression, 1.6 Crane rockers, HOT cam, etc. Don't know the Hp but it's a bunch. Based on every thing I've read the Hp is between 425 and probably 460.

It really isn't such a bad trail motor. However, I've got a SM420 behind it and hate it. I used the SM420 becaue I've got a CJ-5. I am looking to go to an automatic. I am pretty sure if you've got an 425 Hp 355 you ain't gonna like any truck type tranny. If you wanna use the Hp use the auto.

I've got a buddy that put a Ram Jet w/ 4L60E in a TJ and it hauls ass with the auto.

Jeeps that go fast are gay, spent two hours in the middle of the night waiting to get out of a dead end trail because the built to go fast Jeep kept overheating and the 225lb gas pedal cover didn't know how to drive so he tore the hell out of the trail and made a big mess of things trying to turn around. We had to winch him twice and he still barley made it through a tight section that I walked through, we're both running 35's, we're both locked front and rear, but he's got a 300hp 350 and I've got a 2.5l cranking out 150hp on a good day with a strong tail wind.

I'm running 35's locked front 44 and rear 60 and no cooling problems. So far nobody has had to wait on me. I've got Hp when I need it. I won't bother to tell you what I think of 4 banger's. To each his own.

Okay, not all go-fast Jeeps are gay, people who think the loud pedal will get them out of every situation are. I'm just cranky cuz my girlfriend chewed my ass for being late and it was mostly because my friend bought a built Jeep and never learned to wheel first, everyone should have to start with no power and open diffs, makes a thinkin' wheeler outa 'ya. I'll run ya cylinder for cylinder anyday of the week, you pull any four plug wires and we'll line 'um up. Just kidding, horsepower is cool, knowing when and when not to use it is da bomb.

I've had a couple of 4 bangers - one in a 42 GPW, a 53 CJ-3B and 55 CJ-5. These are what I learned to wheel with. So I did just what you said learned to drive first. Had a 304 V-8 from 79 till 99 and loved it. I just wanted to put FI on the 304 and got carried away built the LT-4, probably wouldn't do it again though. A 350 Hp Ram Jet would be just fine now. The V-8 thing is a carry over from my drag racing days.

Oh I had a 4 cyl diesel Rabbit - can't get any less acceleration than that. I loved the thing.

But I agree a lot of people put in race motors and don't take care of upgrading their drive train and taking care of things like cooling. These same people think the loud pedal solves everything. The rock crawling competitions are encouraging people to use the loud pedal more than skill.

Sounds like an awsome 383 engine. I am not building a go fast jeep but I am sick of the doggy 1988 I-6. The new 4 bangers can make more power than me. My 355 came out of an old 83 camaro I had it in. Why not use it. It runns great. I have 10.2 compression. Roller rockers. a solid lifter cam with 294 duration and .525" lift. I love a lopy motor. :eek:

Doc Johnson, we should get together and talk horsepower some time. Nuthin' like it. :) This coming from someone who just hung the block for the ~450 Hp 401, for a rockcrawler, on the stand.
There is a time and a place. I ran a trail this weekend where I didn't need to use more than crawl RPM once, and it actually had me rethinking dropping the monster motor in. But I've since come to my senses.
I look at it this way, it's like a 250:1 crawl ratio. Don't need it? Run in 3rd. Don't need the horsepower? Don't nail the throttle. It's easy, really.

Originally posted by Slagburn
Doc Johnson, we should get together and talk horsepower some time. Nuthin' like it. :) This coming from someone who just hung the block for the ~450 Hp 401, for a rockcrawler, on the stand.
There is a time and a place. I ran a trail this weekend where I didn't need to use more than crawl RPM once, and it actually had me rethinking dropping the monster motor in. But I've since come to my senses.
I look at it this way, it's like a 250:1 crawl ratio. Don't need it? Run in 3rd. Don't need the horsepower? Don't nail the throttle. It's easy, really.

Colorado :eek: :eek: I need to wheel up there on some mountains!! That is what my end dream is. To crawl around at about 3,000 RPM going two miles per hour. I love the sound of a strong engine. Infact this 88 YJ is the first vehicle I have owned without a V-8. It is killing me.

I love the sound of a big motor as much as the next guy, but it pains me to hear that same grumbly motor stalling and sputtering because the super mega cam and 14:1 compression with a 1150 Dominator on a single plane intake won't let it idle below 2000 rpm, or get pelted with rocks because the hair trigger throttle is more like a toggle switch, idle, or WOT. I've had several big motored rigs and loved them for blasting the dunes, but I love my 4cyl in the technical stuff. Not saying it can't be done, just saying be careful, choose a setup that will allow precise throttle control and smooth performance and you'll be a happy camper.

Originally posted by 4Bangler
Okay, not all go-fast Jeeps are gay...

It's not the horsepower I like so much as the TORQUE. There's nothing like being able to idle right up to a ledge at .002 mph with everything locked in and have all four tires just sit there and keep on turning without having to touch the happy pedal. You find you have a lot more control in almost all situations (except for mud :D ) when you have that mountain of torque in reserve and don't need to slip the clutch all the time.

IMHO,
Jake

I have to agree with Jake.

People who are used to wheeling with stock fours and sixes (like I was) say "holy fawk" when they realize they can have control, go slow, easy AND power it if they need to.

In the immortal words of Slagburn :D :

"I look at it this way, it's like a 250:1 crawl ratio. Don't need it? Run in 3rd. Don't need the horsepower? Don't nail the throttle. It's easy, really."

This is wisdom.

Torque is great, but to climb impossible rock climbs, such as competition courses, you really do need to have instant HP available to launch you up and over impossible crawl spots.

My personal opinion is that I would never put an expensive built engine into an extreme rock crawler.
When your running your engine nearly all day long at 700 rpms, on 45 degree angles, and very often with little oil pressure, you really dont want an expensive engine. You can also very often get your self righted after a rollover by keeping the engine running and turning the tires in forward and reverse, untill something grabs.
I like the idea that if my engine is subjected to oil starvation, and comes up lame at the end of a hard day of wheeling, I can replace it with my bolt on parts and a junkyard replacement.
For about $700 and a weekend of work, I could have another engine in place and ready to wheel.
Try that with a $3000 mill.

That is a problem, and that is also why I'm installing an oil accumulator.

400 HP engine, BTDT.

I recently spent an evening changing out the 300/310 degree cam in my 355 for a nice smooth 272 degree one. That was easily one of the best moves I have made with the Jeep.

The rough idle was fun to listen to, but the smell of the raw fuel in the exhaust on the trail, the horrendous fuel economy and the lack of low-end control made driving it on the trail a lot more work than it needed to be.

The new cam pulls much better off the bottom, will lug down to 350 rpm and keep pulling and although it doesn't spin to 7000 rpm like the old one did, will still rev pretty hard.

Go ahead and keep the rest of the built engine, just don't go overboard on the cam selection. All the cam grinders say to go conservative on the duration and their advice was never more true than for a trail rig.

Yep, got it covered. ;) Thanks.

I love a lopy motor

You’re braver than me. I hate descending a long hill with the idle loping up and down. Makes my neck hurt just thinking about it.

Apparently you don't know the difference between a big cam's lopey idle and a shitty running engine's hunting idle. :flipoff2:

Only cause I aint been in your heap yet :flipoff2: back at ya bro hehehe

Put a 700r behind it. Will work killer on the trails and also fast as shit on the street. You can also put in a higher stall converter to help out on the slow stuff with your tall cam. As far as those 4 banger people get the fawk out of my way when pulling hills:flipoff2: