401 to cj7 engine swap. Pros and cons.

[cambam]

I am considering putting a 401 in my cj7. It is the one out of the j truck blue goose wrecked, an it is already bolted to a tf727 trans. Anything I should know, Pros and cons about pulling this off? I would like to keep my dana 300 t case. Any and all info, sugestions and oppenions are wanted. Thanks.

 

[53 willys]

401's run hot. I had a j-10 with 401 and it ran hot someone told me that they made the cooling passages in the engine to small, so it takes a pretty good size radiator to keep them cool. My vote is to swap a 350 Chevy in. Parts are stocked at every parts store, so you don't have to go home early from a trip because you cant get parts. just my .02

but Chris durnham (sp?) had a 401 in his comp buggy with redneck fuel injection and did stuff you would think were impossible with a carbed 401 so who knows.

 

[cambam]

Will the weight of this engine be a problem? I had a guy tell me that this motor was too heavy for a cj, but I dont know if he knew what he was talking about. is it any heavier than any other V8?, and would the weight make you "front heavy?"

 

[KCJ401]

A 401 will drop right in any CJ-7. I have been runnig 401 in a CJ for years no problem what so ever. As for cooling issues they usually result when a 401 has been bored over .060 the cylinder walls get thin they will get hot. Most times this can be overcome by a 3 core radiater and a 7 blade fan with a fan-clutch and of course dont forget the shroud. With this setup mine rarely if ever goes above 210.

A tip when installing the 401 if you plan to use the factory style manifolds .. on the drivers side use CJ style V8 manifolds not full size jeep manifolds , They CJs will give you MUCH more clearance even when running an auto.

The 727 tranny will work with a 300 transfer but if you want to clock it up flat you will likely need to run a skinny thick wall front shaft as clearance tends to get a little close.

Weight is not an issue.. AMC V8s with aluminum intakes weigh in approx the same as a dressed 4.2

 

[53 willys]

sound's like BS to me, there are tons of cj's with v8's and no problems. I dont know what the weight is but it gotta be close to all the other v8's out there.

 

[53 willys]

A 401 will drop right in any CJ-7. I have been runnig 401 in a CJ for years no problem what so ever. As for cooling issues they usually result when a 401 has been bored over .060 the cylinder walls get thin they will get hot. Most times this can be overcome by a 3 core radiater and a 7 blade fan with a fan-clutch and of course dont forget the shroud. With this setup mine rarely if ever goes above 210.

A tip when installing the 401 if you plan to use the factory style manifolds .. on the drivers side use CJ style V8 manifolds not full size jeep manifolds , They CJs will give you MUCH more clearance even when running an auto.

The 727 tranny will work with a 300 transfer but if you want to clock it up flat you will likely need to run a skinny thick wall front shaft as clearance tends to get a little close.

Weight is not an issue.. AMC V8s with aluminum intakes weigh in approx the same as a dressed 4.2

there you go!!

 

[cambam]

so the trans will bolt up to the 300 tcase? Or do I need an adapter?

 

[KCJ401]

so the trans will bolt up to the 300 tcase? Or do I need an adapter?

the TF 727 will bolt directly to the 300 tcase, but to get it to clock up fairly flat you will need a clocking ring. The factory clocking of the transfer and tranny will not let you get them flat. heres an article to explain it better.
www.jeeptech.com/wiki/index.php/Transmission/Conversion/TF727

 

[Bud]

I swapped in a 401 in my 1980 CJ-7 and that thing ran so cool that I would never have to shut it off when down in moab in the middle of summer! I used the stock radiator from the Wagoneer donor and a normal motor mounted 5-blade fan. I also used the stock tranny cooler that was built into the radiator. The only time I ever had a problem with that motor and TH400 was when I got the wrong flexplate (304/360 weighted differently) that made a bad vibration and made me heat up. When I replaced that everything was cool. The AMC's appear to be smaller in size and pack a hell of a punch, also the distributor is in the front instead of the rear like the Chevy 350. This makes fitting and working on the motor much easier in the tight compartment. I used the stock manifolds and welded the hole shut for the smog crap. On the engine mounts I used a mix of stock mounts from the CJ and Waggy to utilize the stock motor mount hole in the frame. I think I only had to drill one hole! That setup lasted me a long time and is still running strong for my buddy.