Engine 83 CJ with I6 threw a rod, should I go to V8?

[BigBobola]

My 83 CJ7 has a straight 6 and I recently threw a rod, the damage was minimum because I stopped almost immediately. But I have decided to do an engine swap for a V8 instead of fixing the 6 and I am wondering the best way to pick other CJ peoples brains on here about the topic.
Thanks for your help!
Bob

 

[CJ]

Well, the first thing I knoticed is that the search was not working correctly so I fixed that. Then I searched for Engine Swap and many links appeared.
This is discussed extensively but here are a few notes.
Going from the I6 to the AMC V8 is very easy and the least complicated. You do not say if you have a manual or auto. The major pieces you would need are frame mounts, radiator, hoses, flywheel or flex plate and other clutch pieces, various wires and other bits.
The next thing to consider is that a Chevy swap is very popular. @TSB8C will chime in soon.

Here is the first post. There are many.

K

Thread 'Engine Swap'

Jun 23, 2010

my AMC 258 i6 / 4.2l six just lost compression on one cylinder,started to burn blue and is pissing oil all over my driveway, Time for a new engine! there is a 1973 AMC 304 v8 in a wagoneer for sale by me,
Jeep 304 Quadratrac 1973-1978 and i was wondering will this just bolt right in with no mods? ive done swaps before so i know how to do it, just wondering if all the bolts will line up and such

oh its a 1985 CJ7 with the bad engine

thanks for the help!

• Kelly

 

[CJ]

Here are search querys.

Search results for query: Engine swap

jeep-cj.com

https://jeep-cj.com/community/search/14459/?q=Chevy+swap&o=relevance

 

[Manic Mechanic]

A V8 swap can get costly and time consuming where as your 6 either replacement or rebuild can be done relatively quick. If your getting a replacement used motor they can be found somewhat cheap and then in a weekend you're back on the road.

I've done both over the years and even diesel swaps. It really comes down to what you do with the Jeep, your budget, and how much you can do on your own vs paying someone else.

 

[CJ]

A V8 swap can get costly and time consuming where as your 6 either replacement or rebuild can be done relatively quick. If your getting a replacement used motor they can be found somewhat cheap and then in a weekend you're back on the road.

I've done both over the years and even diesel swaps. It really comes down to what you do with the Jeep, your budget, and how much you can do on your own vs paying someone else.

100% true, get a used AMC 258 i6 / 4.2l or evan a FI 4.0 with the necessary computer and it's a one day drop in.

 

[TSB8C]

"The next thing to consider is that a Chevy swap is very popular. @TSB8C will chime in soon"

Thanks CJ. I've done the Chevy V8 swap in three CJs, including my current rig. Easy every time and love it. The SBC is so universal in terms of availability, parts, customization options, ease of service, etc. Good power-to-weight ratio and just plain old good power. I have a 350 (5.7L) fuel injected 420HP in my current rig and love it. Now mine is a daily driver in Houston traffic, with my offroad use consisting of camping, deer/quail hunting trips, etc. I don't do extreme mudding or rock crawling like some others do. So as Manic said, look at what your primary use(s) will be and make a decision according. I'll disagree on one thing he said though - forget budget. Yea, I know that's important. But make sure you don't limit yourself and end up with something you're not happy with. When I first swapped the engine in my current rig, I bought a wrecked Corvette with a Chevy 350 and 5-speed manual in it and put that in the CJ. Got tired of all the shifting with that 5-speed manual in Houston traffic and trying to eat my What-a-Burger wile shifting. Remember, mine is a daily driver. While it wasn't in my original budget, I then decided on a 700R4 auto to get away from all that shifting, but retain the Overdrive for highway driving. So swap the tranny again, re-do drive shaft lengths, different adaptor for the Dana 300 , Lokar shifter, tranny cooler, etc - stuff I hadn't budgeted for originally. But I'm much more happier with the outcome and my daily driving experience is so much more fun.

You want cheap - go cheap. You want power/fun - SBC or LS. You want easy cold starts and smooth running - EFI. Just my (soon to be .05 cents when the penny is gone).

 

[BigBobola]

I really appreciate the info so far guys! I am looking at a rebuilt AMC 304 , I have heard that would be the least painful V8 swap in terms of cost and work, I am also considering just going with another 6. I am 64 years old and a disabled veteran so I don't want to kill myself doing this, my mind says.....This will be easy, but my body knows better! Thanks again, and any further info would be appreciated. One more thing, has anyone ever done business with Gearheadengines.com?

 

[CJ]

The AMC V8 is the easiest swap. If you are looking for a rebuilt AMC V8 the 360 is the most common and has more HP. The swap is identical and usually cheaper (engine wise.)

 

[Manic Mechanic]

If your older retired and limiteed go with the inline 6 can be done in a few short hours

 

[Dakardad]

You didnt say what tranny you have. If you have the T-5 your Limited its a POS anyway.
Lots of good swaps out there as CJ said. One thing, everything you need for the 6 is there. Easy peesy. But, if you want the 8 dont put it in front of a POS tranny. Often times people get more satisfaction from a tranny swap. I hate smashing my whataburger too.
I recently rebuilt my AMC 304 . Im found the parts supply drying up and prices ballooning. For the 6 no worries. Lots of modestly priced upgrades too. The SBC is a great change but requires some more thought on the package.
An 8 is not magic. Think about the package.
It'll work out.

 

[Manic Mechanic]

You didnt say what tranny you have. If you have the T-5 your limited its a POS anyway.

I have the T-5 and it's great I've been driving and wheeling the out of it for almost 20 years. The biggest problem with it is people putting the wrong fluid in it or trying to run it behind a V8. It definitely won't hold up behind a V8 or at least not very long. But it's perfectly fine behind the inline 6.

 

[Dakardad]

Im glad you like it ManicMech, Ive never seen one last but l dont know how you use yours or your set up.
Given bigbobolas consideration of an 8, l thought it might be wise to consider.

 

[Manic Mechanic]

I would never put one behind a V8. Won't hold up. When mine finally does bite the bullet I'm going to switch to an ax15

 

[CJ]

I would never put one behind a V8. Won't hold up. When mine finally does bite the bullet I'm going to switch to an ax15

Stupid POS Transmission .

 

[BigBobola]

Hey All,
Thanks for all the great input! As much as I would like to have some more HP I think the smartest solution, all things considered, is to go with another I6, probably late April/early May, I will let everyone know how it goes.
Bob

 

[Belizean]

I was thinking the same. 6-AMC 258 i6 / 4.2l . Enough power where you live unless you are driving on I5 all day long. Welcome. My brother lives in Eugene. Wish I was driving mine in that area.

 

[BigBobola]

I was thinking the same. 6-258. Enough power where you live unless you are driving on I5 all day long. Welcome. My brother lives in Eugene. Wish I was driving mine in that area.

Thanks Belizean! Yeah, I am planning on zero I5 driving. Hunting, camping, and mudding is the only reason I bought it. I grew up here, there used to be so many great off road trails but most have gotten closed down by a certain type of people. Anyway, thanks again!

 

[Belizean]

At least the areas you live around, a couple minutes down the road you are still out in some beautiful areas, minus burnt areas. An hour or 2 and you are in the lakes mountains or the beautiful coastal areas.

 

[Kweimer]

I weighed this argument in my head quite a few times since i bought my 7, in the end i stuck with the AMC 258 i6 / 4.2l , lighter, more down low torque, not a significant increase in power between AMC 258 i6 / 4.2l and AMC 304 stock for stock. To me it didnt make sense to reinvent the wheel, the I6 motors are generally tough as nails and last quite a long time and withstand a good bit of abuse, keep the rpms low (under 3500-4000) and they are fantastic. There is also the consideration of cylinder wear characteristics, the i6 cylinder is straight up and down and tend to wear evenly where a v8 on an angle wear a bit egg shaped, a hone is easier on an overhaul than a bore anyday.