Questions on AMC 304 Conversion

[KenParent91]

Hey everyone,
I have an 84 CJ7 with a manual 4 speed and 2.1L motor. I'm looking to use this keep for a more consistent driver, not toooffroad very much as it belonged to my grandfather, and want it to last a long time. I was looking at swapping the motor to a AMC 304 AMC for more horsepower and such incase I drive on the highway. Is this a good option, and I'd so, can it be swapped without much modification to the Transmission and such? Thanks

 

[jp360cj]

The stock 4 cyl in 84 would have been the 2.5L AMC (AMC 150 cu in). Is that what you still have, or was it swapped out for some sort of 2.1L?

Also, is your Transmission shifter a curved stick, or straight stick? If it's curved, then it's probably a T-4 and not up the task of V8 power.

The AMC 258 i6 / 4.2l to AMC 304 is a pretty straight forward swap, but I don't know if the AMC 150 to AMC 304 is different.

 

[KenParent91]

You're correct it has the 2.5. and it does have the ford T-4 Transmission , so maybe I should try to find a T-5 Transmission to go with the motor? Thanks, I'm new to all of this, and am learning everything as I go along with the rebuild!

 

[Petescj]

Not really much horsepower difference between the AMC 304 and AMC 258 i6 / 4.2l . The T-5 isn't really any better than your T-4 other than the Overdrive gear. If you want a strength upgrade I'd go with a T-176 over the other Cj transmissions. I'd probably look for a 360 instead of a AMC 304 as well. Bolts up the same. You'll need new exhaust and motor mounts along with some wiring harness modifications.

 

[JR74CJ5]

Keep in mind smog laws.

Otherwise, it really sepends how far you want to go with time and money down the rabbit hole right?

If you had a lot of both, and you just want a nice looking cj that drives great, i might look into a fuel injected newer engine and a auto tranny.

You can have a good ride in a carbed v8 with stick still too, but for comfortable driving and all around reliability, technology has come a long way.

I love wheeling mine and love the old v8 sounds so building a nice 360 for it. Since i love wheeling i love my granny low chevy 4 speed.

All in what you want / like.

But for easy swap, i’m not sure about going from 4 to anything else personally... novak adapters also is a good source for drivetrain swap info.

Novak Conversions Home

 

[Hector55]

I had a AMC 304 in my 82, it was a dud so I looked to replace it with another AMC 304 , which was also water corroded. Finally my mechanic said he had a chev 350 fuelie from a truck did I want it . Having had a couple AMC 258 i6 / 4.2l 's 1 302 chev and a jeep AMC 304 I didn't hesitate . The 350 starts every time ( and I live in Canada) is a daily driver makes great power ( a bit too much) and can be plugged in and diagnosed. I realize some cj owners are purists, I get that , but if you want reliability and consistent power this is a great way to go. Just my 2 cents.


Sent from my iPad using Tapatalk

 

[hole]

Hey everyone,
I have an 84 CJ7 with a manual 4 speed and 2.1L motor. I'm looking to use this keep for a more consistent driver, not toooffroad very much as it belonged to my grandfather, and want it to last a long time. I was looking at swapping the motor to a AMC 304 AMC for more horsepower and such incase I drive on the highway. Is this a good option, and I'd so, can it be swapped without much modification to the Transmission and such? Thanks

Everyone brings up good points and suggestions, but have you considered a fuel injected AMC 258 i6 / 4.2l or 4.0? Not sure about your neck of the woods, but out west they seem to come up pretty cheap and frequently.The T-4 /5 are not the strongest, but if not abused should hold up behind the I6. If you've got money to burn though, we'd love to help you spend it

 

[Colorado Yeti]

I have owned 25+ CJ's in my life, both 6-cylinder and V-8's. Some with the 6 were quite peppy but most were complete dogs, especially > 35mph. Most of the AMC V-8 CJ's were very powerful but a couple were dogs. In general, I think there is no comparison between the AMC 258 i6 / 4.2l and the AMC 304 .......the AMC 304 is a far superior alternative if you want decent power. I did a 350 chevy engine conversion on my old AMC 304 CJ7 and eventually converted it back to an AMC 360 V-8. That AMC 360 was crazy fast and ran circles around the 350 Chevy in the same Jeep, so I have to respectfully disagree with the author above.

360's are ubiquitous, relatively cheap and make more power than the AMC 304 . If you are going to do a V-8 conversion, might as well do a 360. Throw that T-4 in the trash and go right to a T-176 or (better yet) a T-18 while your at it. Absolutely consider smog restrictions in your area. It is horrible to spend a few thousand dollars and then figure out that you cannot legally register it.