4.3 in a Jeep

[bspeth]

Has anyone ever tried fitting a 4.3 into an automobile application? Pros and cons. It would be backed by an SM420,Dana20,and 4.56s.

 

[Scott Danforth]

your talking the GM 4.3 that is found in hundreds of millions of trucks that just also happens to be used in a few hundred thousand boats too?

yes, the 4.3 used in boats comes off the same engine assembly line used to make engines for Sierras, S-10's Sonomas, etc as well as generator motors, trash pump motors, gas compression motors among a few other uses.

Companies like Volvo and Mercruiser then buy these motors as long blocks and marinize them.

 

[bspeth]

Would the marine cam be good for use in an offroad vehicle? And my other question would be what would I need to mate it to the 420?

 

[Scott Danforth]

Would the marine cam be good for use in an offroad vehicle? And my other question would be what would I need to mate it to the 420?

Marine cams are mild RV cams (cant get too radical because of reversion - nearly same as found in Trucks (not cars). However there are probably better cams out there for your specific off-road need.

you would need a GM bellhousing from a V6/V8 to bolt it to the 420.

however if this is going into a jeep, there are much better motors for a jeep. I myself like the good old 5.7 liter or a Cummins 4BTAA for grunt motors or an aluminum 6.2 LS3 running the accessories from the 5.3 front drive LS. fits really nice with over 450hp and less weight than the 4.3 you are thinking about.

 

[bajaunderground]

http://www.advanceadapters.com/categories/jeep-tj-packages/277/

They will have everything you'll need (advance adapters). It used to be a fairly common swap as the 4.3 was a good match hp vs. weight. Once Jeep had the 4.0HO, it was not as common. I agree with Scott, the 5.3 are a better swap for a bunch of reasons. AA also has all those kits as well.

 

[thumpar]

Unless you have the 4.3 already go with a 5.7, 5.3, 6.0 or 6.2. The 5.7 might be the easiest since it is a common one put in jeeps. But the 4.3l is a very common motor. I have had 3 safari vans from 87 to 97 that had the motor.

 

[oldjeep]

What kind of jeep? 4.3L is a good choice for some of the older models that require major crossmember surgery to install a V8. I had a couple of the Buick V6's (225 and a 231) in a 46 Willys I owned.

 

[bspeth]

It is a 58 Willys CJ5

 

[Scott Danforth]

Need to see pics of the jeep

I would recommend to upgrade the axles to Dana 44's vs the Dana 20s.

the CJ5 is extremely light, my first recommendation would not be a 4.3, however they are plentiful and cheap. is your intention a low $ toy, or a rock crawling beast, farm mule? for the CJ5, I would recommend the L-52 ATLAS 5-cylinder from the Colorado/Canyon

I tend to over-build everything.

 

[oldjeep]

It is a 58 Willys CJ5

V6 will be a heck of a lot easier than a V8 due to the front cross member locations. A Buick 225/231 would be a super easy swap too. Plenty of power for a rig that light, Even by the time my CJ2a had 37" tires, a commando frame and 102" wheelbase a 231 was plenty of power.

 

[oldjeep]

Need to see pics of the jeep

I would recommend to upgrade the axles to Dana 44's vs the Dana 20s.

the CJ5 is extremely light, my first recommendation would not be a 4.3, however they are plentiful and cheap. is your intention a low $ toy, or a rock crawling beast, farm mule? for the CJ5, I would recommend the L-52 ATLAS 5-cylinder from the Colorado/Canyon

I tend to over-build everything.

58 CJ5 doesn't have AMC 20 axles, it has a Dana 25 front and Dana 44 (2 piece shaft) rear

 

[oldjeep]

FWIW, my 2a had a front 25 and Lincoln locked 2 piece Dana 41 in the back up until I went from 33 to 35" tires. The old axles are pretty tough.

 

[Scott Danforth]

V6 will be a heck of a lot easier than a V8 due to the front cross member locations. A Buick 225/231 would be a super easy swap too. Plenty of power for a rig that light, Even by the time my CJ2a had 37" tires, a commando frame and 102" wheelbase a 231 was plenty of power.

it doesnt take much to build a killer naturally aspirated 300hp 231. I had one in my 73 Opel GT that I put into an S-10 later on. the 4.1 (siamesed bore block) would also work anywhere the 3.8 sat.

58 CJ5 doesn't have AMC 20 axles, it has a Dana 25 front and Dana 44 (2 piece shaft) rear

However the OP in post 1 stated he was using Dana 20 (AMC20) axles.

 

[oldjeep]

it doesnt take much to build a killer naturally aspirated 300hp 231. I had one in my 73 Opel GT that I put into an S-10 later on. the 4.1 (siamesed bore block) would also work anywhere the 3.8 sat.



However the OP in post 1 stated he was using Dana 20 (AMC20) axles.

Dana 20 is a transfer case. AMC 20 is an axle

 

[bspeth]

This particular set up has a Dana 30 up front and a 44 in the rear.Thanks for the feedback,ifn you have anything else please post it.At this point it has no engine so of course it would be nice to do it right once.

 

[thumpar]

The 231 is a great motor and since you are going to be working in a tight spot I would not want to try a V8. I had a car with the 3.8 in it. I don't remember how many miles were on it but it was over 200k when the tranny finally gave out. The engine still purred though.

 

[MTboatguy]

I have owned 4 jeeps, 3 CJ5 and a CJ7 and I will continue to take the 258 straight 6 that AMC offered, that sucker is a strong, good fuel mileage engine that will do anything you need in that particular body!

 

[oldjeep]

Don't think they ever put the i6 in the early cj5(54-64), the later bigger cj5 got the i6 and v8 options

 

[bajaunderground]

I think what you're trying to put it into the 4.3 will be a good swap. In 1988-1992ish they put out around 180hp and 200ft-lb of torque (if my memory serves me right?). You should be able to source all the parts you'll need from a junk yard. The motor mounts may have to be custom made or use the previously posted company (AA) as they more than likely will have them ala carte? oldjeep- I dig that old CJ. I've had 4 jeeps in my life...1979 CJ-5 (258ci), a late1986 CJ-7 (258ci, factory 25 gal fuel tank and a Dana 44 rear), 1979 CJ-7 with fiberglass tub, AMC '69 390ci (dyno'd around 400HP) and my 2000 TJ with Dana 44 rear, NVG 3500 and 4.0L. I miss the 79 CJ-5.

​~Brett