What I got is a 79 Cherokee full size with an AMC 401 V8, TH400 tranny and a Quadra Trac T case. I suspect the 401 needs to be rebuilt.

So the question is, should I rebuild the 401 or locate a rebuilt Caddy 500? One thing I like about the 401 is besides being not the usual thing, it's also an official Jeep engine. But would there some an advantage to using the Caddy engine? It won't be lifted much and will be used for towing and getting the family and camping gear to places remote to the usual crowds

most caddy motors put out around 500lb/ft of torque so yes there is an advantage to running one. Also gives you a chance to get rid of that crappy transfer case :barf:

The 70 and 71 500ci caddys put out 550@3000 and 535@2800rpm lb torque respectively the 72-73 put out 385@2400 the 74 thru 76 put out 380@2000..

The 71 Amc 401 put out 430 lb torque@3600rpm the 72 thru 75 put out 345@3300rpm

Originally posted by hy_desert_4wheeler
The 70 and 71 500ci caddys put out 550@3000 and 535@2800rpm lb torque respectively the 72-73 put out 385@2400 the 74 thru 76 put out 380@2000..

The 71 Amc 401 put out 430 lb torque@3600rpm the 72 thru 75 put out 345@3300rpm

they put out the same amount of power to the wheels, but the numbers are just different. it's net power vs gross power. the 500 swap will be a headache, but you'll have 100 more cubic inches to play with in the end. the AMC 401 is plenty powerful enough (plus it has forged internals stock) and when built properly, can make an incredible powerplant.

i have never been a fan of amc and still aint. do the caddy 500.

Originally posted by yjtj
i have never been a fan of amc and still aint. do the caddy 500.

why not? the 401 has all the advantages of the 360 and none of hte disadvantages

While there is NO substitute for cubic inches, the 401 is a very easy conversion. Just make sure you get your cooling issues taken care of first. I have a remote engine oil cooler, 4 row radiator, factory fan shroud and a 6 blade fan. It has been running cool since the install and it even is .060 over.
Do the 401 and save yourself some headaches...

Ricky...seeya...

ih doing a 401 conversion aint easy but it is well worth it i built mine to 71 specs with and aluminum intake and headers and couldn't be happier. The caddy swap would be a big pain in the ass if for no other reason it is a big block and would barely fit between the framerails as well as being heavy, mine is 75lbs lighter than a 350 and 100lbs lighter than the 258 i pulled out

Originally posted by swamper502
ih doing a 401 conversion aint easy but it is well worth it i built mine to 71 specs with and aluminum intake and headers and couldn't be happier. The caddy swap would be a big pain in the ass if for no other reason it is a big block and would barely fit between the framerails as well as being heavy, mine is 75lbs lighter than a 350 and 100lbs lighter than the 258 i pulled out


Are you saying that a AMC 401 is 75lbs lighter than a small block chevy? How much does the 401 weigh?

caddy! caddy! caddy!

The Caddy is only 45 lbs heavier than a 350 if you put an aluminium intake on it. "There's no replacement for displacement" :jeep:

no an amc401 is about 35lbs lighter than a 350 but then i added a aluminum intake and headers and got another 40-50 lbs not a whole lot but pretty cool

my $.02.... build the 401... unless you like the hassle of shoehorning in the Caddy motor... but since you already have the 401 I'd say all signs point to it.

While the 500ft lbs of the caddy motor just plain rocks, the conversion might be a real pita.
Make the 401 breathe...2.5" exhaust, K&N air filter, extreme top
Upgrade the ignition...TFI or DUI
Woila...close to 400ft lbs of torque on a mostly stock motor which weighs less than a sbc. Make sure to keep it cool though. I have a 401 in my beater...beats to hell any sbc I've ever owned. my0.02

I am in the process of building a 401, so I feel your pain. It will be nice when it is done, but for all the money I have in machine work and parts (which is all I am paying for) I could have built a mean 350 with fuel injection. And I havent enve started to assemble my hybrid fuel inject, which I will no doubt end up paying someone to burn multiple PROM chips for untill I get it dialed in just right.

But, you gotta lave AMC V8 power:D

or is that an oxymoron;)

yeep, you do know that howell and holly both make injection kits that bolt on. I would personally go with the howell but i wouldn't mess with a custom system

Hey yeep..do a search on tpi guy...he makes custom fuel injection systems for AMC motors.