swapping amc 360 for 400... is it worth it???

[j20krawler]

theres an old cj for sale that has an amc 400 and if its running fairly good, do you think it would be worth it to switch out my crappy running, riser clicking belt squeeking 360 for the 400, i also want to know if all the smog stuff from the 360 will go onto the 400? (i live in california). all info would be grreeaatt!

[Headhoncho]

If it's an amc motor it's got to be a 401. It's definitely worth it as long as it runs better than what you already have. Everything should swap over to it. Look between the starter and the motor mount on the block for the cid casting.


JR

[billyrb]

401's are by far better motors. If it's been rebuilt, find out how far it was bored (if at all). If 60 over, you might want to pass as it'll be difficult to keep cool versus stock bore / 30 over.

[MrThorn]

I just learned you're gonna need a 401 flexplate for an automatic tranny, the 360 and 401 flexplate are balanced differently.

[dusty]

its a bolt in, and i mean EVERYTHING is bolt in. the exterior of the two engines is identical minus a few 401's out there having car heads on them and lacking the bosses and holes for the accesories (rare instances) everything else is straight off one block and onto the other. and the emissions map on the 360 is big enough that you can probably get through it just fine. we got my 79 through it twice before i opted to "rebuild" my 1974 wagoneer with a 79 cherokee body. either cover the numbers on the side of the block most smoggies wone know to look there but if they do you are red flagged. Also fill up with lots of alcohol before your test and make sure the engine is hot... in my case my buddy worked for a dealership he was allowed to use the equiptment on weekend so we would wheel min in put it on the machine and dial it in till it was under the highmark might not have run great but would then run it across town to the smog ref/ inspection station have her tested pass and go home. dont test where you know anyone.... you dont want to cost them thier license. because of accusations of foul play when there never was any.

dont let cali smog deny your fsj the power it deserves there are ways around that without ever bribing a smog tech...

the 401 is a GRWAT power plant for your fsj. what tranny do you have 727 the 727 flex palte for a 401/727 is out of the 71/72 matadors/ ambassadors IIRC or th400 flex plates are a dinme a dozen from 74-78 fsjs both are available. if the engine came in front of a th400 there is a crank centering bushing you will have to remove. otherwise if its in front of a t-18 just take the pilot out if you are putting it in front of an auto... oh yeah if you have a th400 you dont need the centering bushing it was a factory thing that made life easy on the assembly line but for the rest of us if its in there or not hasnt seemed to hurt any rigs yet.

good comment on the over bore. 20,30, 40 seem to be ok, 60 likes to heat a little. nothing a set of sleeves cant fix, shame they took it out so far if thats the case but the block isnt done yet.


buy that baby find out what cam they put in it though. other than that not much else to say..hang on