Engine rebuild, or engine swap???

[MacGordon]

I am finding that my '77 Wagoneer is loosing its power, slowely but surely. It has a loud clatter when it runs, and dies from time to time. The engine is a 401 and I like it in spirit, but for running, it's old and tired. To be honest, I'm quite baffled that I have been able to drive it this long. After getting it started after purchase ($250), I planned on getting the engine rebuilt or swapped so it wasn't a big deal whether it worked or not. I have put a lot of stuff into it as you can read below. This thing was bone stock. Now that this long winded story is over, what should I do.

I have been told that a GM 350ci, with an adaptor to the th400 is an easy swap, not to mention inexpensive parts when fixes are needed. Or...should I rebuild the 401 and experience the same problems I have now eventually down the road. I just need enough performance to scoot down the road with a small 6.5'X12' steel cargo that has a ATV in it, when I'm on a hunting trip.

[EJ10]

A 350 might be cheaper to build or buy but by the time you get all the extras (carb, starter, alt, etc.) It won't be any cheaper. In my opinion rebuild your 401. It will be much simpler and cheaper.

[89grand]

When you say "experience the same problems down the road..." are you referring to having the motor eventually get tired again? You're going to eventually have the same problem again no matter what engine you put in there. From my experience the chevy small block has one of the shortest life spans of any American v8 I can think of. Every chevy small block I can think of starts smoking before 100,000 miles or throws a rod. This isn't something I've only seen once, I have seen this MANY times. Rebuild the 401, it may cost more but you'll be glad you did. My Grand's 360 has 138,000 miles, it burns no oil, does not smoke, is not tired and it doesn't need a ring job or valve job like a chevy will before 100K. Now I know I'll be attacked for saying these things but I stand by them. The chevy small block is a great engine to build for some power or to build cheap but they are not a long running engine even if some one here claims to have 250,000 miles or something ridiculous like that. Again this is just my opinion, I'm sure running them will claim otherwise.

[Zac]

How many miles are on the engine? Before you should commit to doing anything I would go to auto zone and buy a compression tester for $30. If you have to rebuild it you can do it for around 1000 which would be probably less than a chevy swap.
500 to machine shop
240 for rebuild kit
250 for reman. heads
-Zac

[MacGordon]

89Grand, thanks for the advise, and same to you Zac. I think you're right, having owned a few older GM pickups in my day. I'm not a hundred percent sure how many miles are on the rig. it says 68,000 something, which could mean 168,000 or 268,000. The previous owner doesn't know, and to tell you more, the Wagoneer looks like it had been abused over the years by each owner. And I mean abused.

But hey, it still runs. I would like to rebuild the 401. I have cool custom made 401 graphics on the thing now. I also like the knowledge of knowing that it was the original engine. And heck, it's hard to find a Wagoneer running around that is powered by a 401.

Anyone know of certain mods I should do if I rebuild the 401?

Thanks again,
James

[Serious Johnson]

Mac:

I second the idea of keeping and rebuilding the 401. It's really a dang decent piece, and only loses to the Chevy in availability of cheap or extreme power parts. What you might save on really cheap rebuild parts will be much more than offset by adapting the foreign mill.

Even if you wanted to make a whole lot of power in the future, you could get nearly as much from the 401 for just a few hundred bucks more, and the whole package would likely be more reliable than a motor-swap kludge.

This is not to say that a Chev motor can't be good in a Jeep -- just probably not on a tight budget.

As for specific mods, I don't really know. There's stuff on the Wild, Wild Web regarding AMC motors. I'd just suggest that whatever info you find on this board about performance of the more common 360s be viewed in context of your much larger motor.

That is to say, a camshaft/manifold/carb/exhaust setup that is just right for a 360 is almost certainly too mild for your 401. Rule of thumb, bump everything (valve events, carb cfm, exhaust diameter) up by at least 10%, and choose an intake rated for max torque at 4,000 revs on a 360 for optimum jump at 3,500 on your 401.

:-

[ March 11, 2003, 04:18 PM: Message edited by: Serious Johnson ]

[Zac]

I am not sure about the 401 but when rebuilding the 360 lots of people get high performance oil pump gears and a stiffer spring(for something oil related). I have also been told to replace the flex plate when doing a rebuild.

Dont take my word for it I dont really know what I am talking about because I am planning my first rebuild right now(and need to know the same info except I need it for a 360). hopefully someone else will tell you what you need to know.
-Zac