Amx engine swap

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   Hey guys, I know there's a special circle of heck for people like me but, our 1968 AMC AMX has a 390 ci in it, and to say the least it's a problem child and I was thinking a engine swap. The problem is I know nothing about swapping. I know the size is about 6.4 liters but I was wondering if I would be able to put in something larger and more modern. Like would a cobra or a ford or gm work? 

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pekenator Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Fan Joined: Apr/01/2012 Location: Kansas Status: Offline Points: 6	Post Options Post Reply Quote pekenator Report Post Thanks(0) Quote Reply Topic: Amx engine swap Posted: Apr/28/2012 at 7:18pm
	Hey guys, I know there's a special circle of heck for people like me but, our 1968 AMC AMX has a 390 ci in it, and to say the least it's a problem child and I was thinking a engine swap. The problem is I know nothing about swapping. I know the size is about 6.4 liters but I was wondering if I would be able to put in something larger and more modern. Like would a cobra or a ford or gm work?

bigbad69 Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/02/2007 Location: Ottawa, Ont. Status: Offline Points: 6666	Post Options Post Reply Quote bigbad69 Report Post Thanks(0) Quote Reply Posted: Apr/28/2012 at 8:51pm
	You're not going to get a lot of love here asking how to put a brand X engine into your AMX. I hope you have your fire suit zipped up. Would a cobra or a Ford or GM work? Absolutely. Is it a trivial swap? Not really. If I could offer some advice to someone who knows nothing about swapping, either find a friend to help you in person, or abandon the idea. There will be fabrication involved, electronics to cobble up, and a host of details to address. Depending upon the engine you choose there may not be anyone on this board who has done the swap before, so no one to guide you through it. I know a BBC can be done as well as a 426 Hemi, I have seen the cars. But don't ask me how it was done, I don't know. I wasn't there at the time. Perhaps you could tell us the issues you have with the 390. There are lots of people here able and willing to help you on that front.
	69 Javelin SST BBO 390 T10

kellysguy Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Mar/15/2012 Location: Mississippi Status: Offline Points: 721	Post Options Post Reply Quote kellysguy Report Post Thanks(0) Quote Reply Posted: Apr/28/2012 at 11:02pm
	Cheaper and easier to fix what you have. I love my 343.

17tamx Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Dec/23/2008 Location: Peoria, AZ Status: Offline Points: 1170	Post Options Post Reply Quote 17tamx Report Post Thanks(0) Quote Reply Posted: Apr/29/2012 at 2:24am
	A cummins 3416 Diesel will drop right in but it will total the front end of the car when it lands in place. Your car will be worth more to an AMC guy with the AMC 390 engine than it will be with a brand x motor. A modern drivetrain will make a very nice driving AMX but the job won't be an easy task for a newbie.
	Kirk P. Fletcher 70 AMX BBG w/Shadow 390 4sp 71 SC360 Wild Plum Ram Air 4sp 67 Rogue Convert 343 4sp 66 Rogue Hardtop 290 Auto 66 440 Convert 232 Auto

FuzzFace2 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/05/2007 Location: Angier, N.C. Status: Offline Points: 10356	Post Options Post Reply Quote FuzzFace2 Report Post Thanks(0) Quote Reply Posted: Apr/29/2012 at 7:57am
	I am with the others what is wrong with what you have that you want to replace it with a belly button motor / drive train? If it needs a rebuild rebuild it. If you want electronic dist you can get them. Want fuel injection you can get them. Want a 5 or 6 speed OD stick trany you can get them. For an auto with OD you would need to adapt a GM but it can and has been done. You want tube controll arms, 4 link rear, coil over shocks front & rear you can get them. All this would still be powered by an AMC motor & rear in an AMC body. If you want X brand drive train then buy X brand body to fit it in. Dave ----
	TSM = Technical Service Manual 75 Gremlin X v8 for sale 70 Javelin 360/auto drag car 70 Javelin 360/T5 Street car

Rogue401 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Nov/26/2010 Location: New York Status: Offline Points: 1280	Post Options Post Reply Quote Rogue401 Report Post Thanks(0) Quote Reply Posted: Apr/30/2012 at 10:37pm
	Every time I read one of these I think back to a guy I knew, probably 30 years ago. I had my 69 AMX with a typical mild 390/4 speed/3:54. He had a show worthy 68 AMX and he thought his 390 didn't have enough power, so he swapped in a pretty hot 327 Chevy. It was a huge undertaking. The way he did it, nothing fit right. The pan hit the crossmember, the steering hit the headers, the distributor hit the windshield wiper motor and on and on. When he got all done, it wasn't any faster than my 390. I have a friend with a street rod shop in Nebraska and he has done a number of Cobra crate engines in early mustangs. Those engines are very wide and only fit the early Mustangs if you use a Mustang II style crossmember and cut out the shock towers. Another thing to consider is when you go to sell it. From what I see on ebay, you can't give away an AMC with a Chevy in it.

ccowx Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Nov/03/2010 Location: Yukon Status: Offline Points: 3510	Post Options Post Reply Quote ccowx Report Post Thanks(0) Quote Reply Posted: May/01/2012 at 12:20am
	Can you explain what the issues with the motor are? What are you trying to achive, power wise? AMC engines are no more difficult to work on or any less reliable than anything else from that era. Unless you are trying for 1000+ hp you should find that most parts, stock or aftermarket, can be had. Whatever additional expense you might find for AMC parts is likely nothing compared to the hassle and expense of a Brand X engine swap. Thanks, Chris

WesternRed Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Online Points: 5796	Post Options Post Reply Quote WesternRed Report Post Thanks(0) Quote Reply Posted: May/01/2012 at 2:39am
	If you just want more cubes then the 390 is fairly easily stroked to around 420 cubes by offset grinding and some custom pistons. Bolt on some alloy heads if you don't want to mess around with the factory ones. Add one of the Edelbrock EFI systems and you are just about done. If you are heck bent on an engine swap then bang for buck, you would probably want something like a big block chev stroker with around 570 cubes. That could get you something like 700-800 HP fairly easily byt don't expect any change from $15K, probably more like $20K by the time you do the trans and the rest of the conversion. Otherwise the modern Hemi would be a little bit closer to home if you just want to experience what 40 years of engine development has acheived. I'm in the process of doing a small block mopar V8 into a 3 series BMW and the main reason for that is that I already had the engine and wanted a cheap light weight body to put it into with decent brakes and suspension. Avoids butchering a classic and having to deal with any rust issues.

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19672	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: May/01/2012 at 12:00pm
	If you think you have a problem child now, wait until you try a swap! It's only difficult if you've never done it before. The problem is everything will have to be custom. Find someone who is familiar with swaps to help and you should be okay. I'm like the others though. The 390 shouldn't be a problem if everything was done right, and should make a lot more power than a 350 chevy. The AMC is as modern as the typical pushrod 350 Chevy -- unless you're getting into LS motors with EFI. Most people know Chevys and know little about AMCs, so they can the AMC. You have lots of expertise here -- keep the Chevy guys away from your motor and give us a chance to eliminate the problems first. You'll likely be happier in the end. If you had an old Rambler (more like mine!) or more common AMC rather than what is considered the most collectible (two seater AMX!!) I'd be more willing to say go ahead with the swap. As it is you have a $25-30K car that you'll be downgrading and have a harder time selling. If it were a Matador, Hornet, Rambler or anything else (except a Javelin) you'd be about even on value if you performed the Chevy swap, especially if it was originally a six cylinder car.
	Frank Swygert

tomjt3 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Fan Joined: Mar/16/2015 Location: United States Status: Offline Points: 6	Post Options Post Reply Quote tomjt3 Report Post Thanks(1) Quote Reply Posted: May/25/2015 at 3:07pm
	AS MUCH AS I HATE TO SAY THIS, I LITERALLY JUST FINISHED PUTTING IN A CHEVY 350 WITH VORTEX HEAD AND TURNOUT 350 TRANNY INTO MY 1970 AMX..IT HAD SUPPOSEDLY A REBUOLT 360 BUT IT KNOCKED AND SMOKED, VIBRATED REALLY BAD,I HAD CHECKED AROUND TO REBUOLT IT, AND IT WAS NOT CHEAP..AMAZING THE ONLY BIG MODIFICATION WAS MOVING MOTOR MOUNTS A COUPLE INCHES FORWARD, THE TRANNY BOLTED RIGHT UP..DRILLED A COUPLE OF HOLES FOR BOLTS IN TRANNY SUPPORT..HAD A NEW DRIVE SHAFT MADE..HEADERS FIT PERFECT.ENGINE ALL CHROME, AND NOW WITH MORE HORSE POWER I LOVE MY AMX EVEN MORE THAN I EVER DID..IT WOULD HAVE COST A SMALL FORTUNE TO TRY AND MODIFY THE AMC 360 TO GET THE POWER I AM GETTING FROM A GM CRATE MOTOR WITH 350 HP...IN AS MUCH AS IT UPSETS PEOPLE, I DON'T LIKE CHEVY ENGINE IN FORD HOT RODS..FOR ME IT WAS MY BEST MOVE, I DON'T CARE IF VALUE GOES DOWN, NOT SELLING IT ANYWAY..BUT I SURE RUNS A LOT BETTER THAN IT EVER DID..SINCE CARS ARE A HOBBY FOR ME, IT TOOK ABOUT A MONTH TO FINISH THE SWAP..TOTAL COST WITH ALL THE CHROME PARTS WAS ABOUT $4000 WITH THE BAND NEW CRATE MOTOR FROM CHEVY....NOT TRYING TO OFFEND THE DIE HARD CAR GUYS, BUT MY AMX GOES LIKE HE'LL NOW AND I LOVE IT....HAPPY MOTORING... Edited by tomjt3 - May/25/2015 at 3:10pm