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Old 07-23-2000, 03:49 AM
Scruffy Scruffy is offline
Join Date: Jun 17, 2000
Posts: 111

I have a friend who is planning on pulling his inline 6 and rebuilding it with as many hi-po parts he can get his hands on. I have a 360 in need of a rebuild and plan on swapping it with a Chevy smallblock (decided the bigblock was too much of a hassle to drop in). I offered him this engine to rebuild in place of his I-6. I am giving this engine to him if he wants it (has no oil pressure whatsoever after 10minutes run time,but still runs,figuring on the culprit being the timing cover.). I told him that if he puts all the hi-po parts on this 360 instead of his i-6,he'll no doubt get more horsepower out of it (in reality,I haven't the slightest clue,I just assume there are as many hi-po parts,if not more,for the 360 than the his current 258) He would like to know a ballpark figure on how much horsepower he will get (little,or a buttload....something along those lines) if he chooses my free 360 to rebuild and hi-po with aftermarket goodies.
Also,he is concerned about any additional work required to drop in the V8 in place of the i-6. Will it bolt-in the same,does it need a bigger radiator,ect.
The final question he seems to have is the reduced gas milage he may encounter. He is more concerned about the increase of HP and low-end torque,be he doesn't want to cut his MPG in half either.
I have received excellent info here,and hope you can help me answer these questions if possible.
If it helps any,this 360 of mine has a new camshaft,lifters and timing components,excluding timing cover.

The bottom line is certainly HP and torque over all......his retired father who used to be a mechanic tells him that the i-6 will come close enough,even as far as "nearly identical" in performance to the 360,but has little personal experience with these particular AMC engines. I respect his opinion,but feel he is way off-base.Plus geez,it's a FREE V8!!! C'mon!

Again,thanks in advance for any opinion you have.
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Old 07-23-2000, 01:46 PM
joe joe is offline
Join Date: Apr 28, 2000
Location: PNWet, USA
Posts: 22,392

I guess you need to define "build for HP".
He looking for 200HP, 300HP, 400HP????
For 200HP the six will do it fine. If you're looking for much more than that the V8 is the only way to go. But you're now talking $$$$$ to get in the 300HP area.
Yup you'll need the 360 radiator with the swap also but prolly even a bigger after market one(3 or 4-core) depending again on the HP goal. The engine is pretty much a bolt in with new motor mounts but you'll still need to deal with mating the rest of the drive train up.
Just curious but if he's worried about cutting his gas mileage why's he building for HP? He's prolly gonna lose 25% mpg's just by dropping in a "stock" 360
let alone a built one.
If he does use your 360 and he wants to get rid of the 258 drop me a line direct. I'm looking for a complete one that's rebuildable.
Preferably a 70's vintage but would take an 80's too.
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Old 07-23-2000, 02:03 PM
JERRY88GW JERRY88GW is offline
Join Date: Jun 09, 2000
Location: Alexandria, VA, USA
Posts: 242

If you friend doesn't take it, I'll pay you for it.

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Old 07-23-2000, 03:59 PM
scotty's Avatar
scotty scotty is offline
Join Date: Jun 12, 2000
Location: dayton,oh,45431
Posts: 6,627
Thumbs up

i recently learned that the core support is differernt between the six and v8 trucks.the v8 radiator is about 2 inches wider,and there is no modifying the six core support to make it fit,youll have to swap the whole core support for the v8 piece,which is very high on the PITA scale. i am currently using a v8 cj 3 row radiator in my grand wag,which is the same width and fits pretty good after drilling a couple new holes. as joe mentioned,youll need new frame mounts and motor mounts. what tranny is he running? will you be donating your tranny as well? the v8 and six use same bellhousing pattern,but make sure the tranny hes using can handle the proposed power output. if its an auto, hell want to use a 727 or th400(what year is his rig?). some say that the t150 is a fairly stout tranny,as far as 3 speeds go,but i really dont know about its ability to wthstand lg amounts of hp.youd prolly want a t18 if you want to run a manual.

dont forget exhaust.but i guess if hes really buildig a HP engine,hell want headers and new exhaust anyway...

how does he use it,and how much power does he need? the six will never propell you to 60 mph in 4 seconds if hes a street speed freak. if he uses it off road frequently,id say go with the six. i personally think you dont need tons of power for 'wheeling,just the right gears.unless of course,he likes to blast thru the bottomless mud pits in 4hi-for mud you need lots of hp to turn the tires quickly so theyll clean themselves. the six can make plenty of power for trail riding,or even crawling around on the its nearly indestructable. i was going to drop in a sbc when mine finally went,but after seeing the abuse my little six takes and keep right on going like nothing happened,ive changed my mind. there is no where that i cant follow my friend with a 360 and t18 in his 79 wag,so i really cant see any advantage of havig a v8,except that now it will be harder to keep cool,and just alittle heavier. and i honestly dont believe that the 360 can run on its side with no oil,or be overheated and still be in as good as the six as many times as mine has. plus been thru an engine fire,and sat completely under water for 5 hours waiting for rescue. i could go on,but ill just leave it at not being able to say enough about how durable an engine the six is.

im going to build a stroker for mine over the winter which should leave me with plenty of power to idle up hills and over rocks.

my 2 cents,anyway

85 grand wagoneer
258/904/twin stick dana 300/dana 44/amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd
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Old 07-23-2000, 04:31 PM
ClarkGriswald's Avatar
ClarkGriswald ClarkGriswald is offline
Master Mechanic
Join Date: Jul 03, 2000
Location: Bloomingdale MI , USA
Posts: 1,477

A good radiator guy can make you a radiator of any size.. they just look up what cores are available at what sizes and find a top and bottom (or right and left) tanks to put on em.. sometimes this is cheaper than buying a particular radiator ... sometimes its not.. doesnt hurt to check it out. try to find a small shop that specializes in radiator repair and customizing. (ie. someone that cares about what they are doin)

88 Grand Wagoneer
D44's front\rear
AMC 360
TF 727
NP 229 (Funky)
Bone Stock (for now)
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Old 07-24-2000, 05:04 AM
RUDY79 RUDY79 is offline
Join Date: Jul 18, 2000
Posts: 50

He should rebuild the 6..
I've rebuilt many a inline 6 and was happy with them. PAW has flat top pistons and RV cams that will make it pull stumps.
And lets face it in the engine compartment on my wagoneer there ain't S#t room under the hood. Changing the rear passenger side spark plugs or exaust manifold is a torture ritual because of the heater box and stuff. My friend has a J10 truck with the inline six and I hate him. Sure I can push 100 beween Vegas and LA with the V8 but we conquered more trails and crested more moutains in that J10 than anything else.
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Old 07-24-2000, 08:04 AM
Master Mechanic
Join Date: Jun 18, 2000
Location: Brookville,PA,USA
Posts: 1,338

Thought I'd tell you the trick I used to swap a V8 radiator in place of a 6 radiator. My '81 J10 with 258 was overheating and the radiator was totally shot so I though I'd swap in a V8 radiator. I ran into that core suppport problem instead of giving up I got out the airchisel, hacksaw, and abrasive saw. Only took about half an hour but I trimmed it out for the V8 rad. and moved the core support/bodymount over then welded it in place. It looks just like a factory job and the new radiator really cools off my 258. Oh and I love my 258 it always works great! Plus its alot easier to work on than a 360, alot less parts!
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