1967 AMC 343 HiPo

[High5]

What do you guys know about these engines???

Power numbers????

Value????

Anything???


Thanks
High5

[gschuld]

I am FAR from the voice of technical experience, but from my understanding they are good motors for their cubic inches. They will never be as desirable as the 390 bigger brother, but they deserve some respect. They do use big valve heads, same as the 390, 10-1 compression and a 4bbl carter sure is nice, the intake manifold design is very respectible for a stocker(can be machined/ported for better performance) The heads flow fairly well, though not as good as the 1970 and up dogleg design(which can be mated to a 343 without too much difficulty). As far as their value. It is not nearly as valuable as a 390 of course. I've seen good running motors sell for as little as 200 bucks, ready to run. Maybe close to a grand if it is in outstanding low mileage original condition(totally guessing on that one). I have a running 343 bolted to one of my engine stands now. One of these days I'll drop it in something to give it some excercise! Are you asking for any particular reason....

George

[High5]

Yeah, I have a line on one here locally. Not sure of the condition, for 100 bucks. I tried to call last night and didn't talk to anyone but a machine. I was hoping I would get a call back. Comes with auto trans I guess.

Thanks

High5

[gschuld]

If you want to put it in a car that you are not trying to get the most performance from, a good running 343 should be a bargain compared to the generally MUCH more sought after 390/401. If you have performance pretty high on your priority list, those 47/58 extra cubes of the 390/401 sure make a difference when trying to get power to the wheels. The 390/401 will generally make your car more desirable/valuable unless your car is otherwise factory original and came with a 343. Hope it works out for you...

George

[rollen dean montoya]

nothing wrong with a good running 343. a friend is running one
in a 68 jav and it has no problems with hitting felonious
speeds in a hurry. dad walked us thru the rebuild. depending
on where you live i would use a heavy duty radiator to help keep things cool. living out here in the desert its a real good
thing to help keep the engine cool .

[High5]

No car here, Jeep :lo1l:

I have a 360 sitting in the garage that needs to be built and a 258 in the Jeep now that runs OK now. I'm thinking I will just stick with the 360 and be done with it. Ok, I haven't even started, but you know what I mean :t:

High5

[gschuld]

Are you talkin CJ or full size? I have a mildly built 360 in my 76 CJ-5...it's FUN! I've got a 401 if I need more...still trying to convince the little demons in my head that it would not be a good idea to go bigger 111!!!

George

[Rhinolined360]

I love my 360! Get that toy built!!

[AMX69PHATTY]

343's came in 2 flavors, 2 barrel @ 9.sumthin:1, and 4 barrel @ 10.2:1 CR
2V's had slightly dished pistons, 4V's had flat tops and rated @ 285 HP I think.
As said, heads are rectangular port, but same as '69 390.
343's had 7/16" head bolts, 360's had 1/2"
'70 & up heads will bolt right on, and I've used the 7/16 head bolts
allthough the '70 up heads have holes for 1/2"
but Step Dowels will need to be installed in the block deck.
Bore is 4.08, same as the 360's, but stroke is 3.28 where 360 is 3.44
343 deck clear is .060, where 360's were .012 i think.
343 is 9.175 deck ht, 360's are 9.208
Same 5.875 rods in 290-304-343-360

Neat thing about 343 blocks is install a 3.44 stroke 304/360 Crank
and available aftermarket cast 360 pistons with 1.58 Comp HT
and whala, 0.000 deck clearance, ok quench, and ok CR with the big 27cc,
or there abouts, cast dished 360 pistons.
Rumor has it 343 blocks have a little more "meat" in'em
and can be bored more than later 360 blocks
and the puzzled look on non-AMC folks faces when you say "343" is rewarding.

[High5]

Phatty,
All of that went right clear over my head. It's a CJ5 that I'm sticking the 360 in.

What kind of power numbers do you get with a 343 with all that stuff you said in there :mrgreen:

High5

[gschuld]

Basically, it will come out as the same displacement as a standard 360, it's just the details work out a little better in the combustion chamber with the 343/360 mix. So the power potential is basically the same, it just helps a bit to keep detonation at bay, which is important. The power potential is more a matter of the cam, intake, head details, compression, exhaust quality, etc.

George