Question about k-frame engine mounts on a J-body

72Dodge

72Dodge

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Hi all,

It looks like I could become the proud new owner of an '83 Mirada (and if so, I would be hanging out here a whole lot more often!)

Situation is that the car has no engine/trans. It was a 318 car, but the engine mount ears have been cut off the K in prep for a big block swap, and the trans mount is also now missing.

I want to put a hot 318 back in the car.

Let's assume that I don't want to go with an engine plate, and that I don't want to swap out the K (since all the front end work has been done already), so I want to weld in new mounting points on the K.

Questions:

- are all small block K mounting points the same, so I could source them from an A, B, C body K-frame?
- if not, could I get them from an F, M, or J body? Or would they be J-body specific?
- what about the trans mount? The car was a 904 car, but I'd be installing a 727. Would I just need to get a trans mount from any J-F-M body, or...?

Any other thoughts?

Thanks for anyone's knowledge on this. I've always liked F, M, J bodies, but if I get this Mirada, it would be my first since I had a '76 Aspen R/T back in the early '90s.
 
easiest way would be to get another FJM k-frame and swap it out, and put all the new parts off the exsisting k on the new one
 
Well, that would of course be one way to do it, but the assumption for my question is that I don't do that. I'm looking for the details on the different types of mounts so I can be informed about the option of welding in new mounts. I'll be honest with you... if it's reasonable to do that, and if I can get the right info to do that, I definitely do NOT want to swap the K-frames. I really think the easiest thing to do would be to weld in new mounts, but I need the correct info to make that decision. But, thanks for the input.

(In other words, I understand that that's one option... I'm looking for info on the OTHER option!)
 
I believe all the older mopars use the same mount with an automatic. Having a 727 or 904 has no difference. Both have trans mount in same spot. For the motor mounts, if any mopar would have the same location on the mounting ears, it would be from a b-body. Most b-bodys will have different ears, but should be in the same location on the k member. There a decent amount of parts from a b-body that will interchange to a j body. If anything, just get location measurements from another j body. Not sure why they would cut off the mounting ears since they make mount adapters to go from small to big block.
 
Yeah, I don't know why either, but that's the cards I've been dealt. I certainly will consider swapping the K, but I want to know all the facts before deciding.

I haven't seen the K yet... they may be cut off in such a way that the location is still obvious, just the bulk of the mounts are gone. I'm not sure. This weems to be the only part of the project that could potentially be a real PITA.

I need to know the shape/style of the ears too, from J to B to F or even A or whatever. Like, say I were going to cut ears off some other K to weld onto the Mirada's.... what would work.

By the way, thank you for the info on the trans mount.
 
Somewhere in the mid 70s, I believe it was in 73 they changed the mount style from the plate style to the ear style. You would be able to use ears off any small block k-member newer than that.
 
either way you'll have to get to another k to get the ears.
I guess the main thing to know is how the previous owner wacked em off to really know what your gonna need
if there's any junkyards in your area, look for 5th aves. they're the most readily available car that you can get a k-frame from (weather you wack the mounts off or take the whole k) and it'll have the trans mount you need
 
Its a pain in the ass to cut off the mounts off the K frame. The way they are welded on, you have to cut them apart, then off the K frame.
 
Yeah, this is really seems like the only PITA part about this project. I'm half tempted to just use a plate to mount it, but I've never done that either. REALLY not looking forward to swapping a whole K. The plan was for this to be an easy project to get back on the road until this twist was thrown at me!

I actually do have a '73 A-body v8 K sitting here I can check out if they're the same ears, but I'm not cutting that one up, I'd have to get an FMJ K whichever way I go this side of a plate.

Any thoughts on using a plate? How much of a PITA is that? Does anyone make one already fit to a J body for small block? Or would I have to get a universal Mopar SB one and cut to fit the J?

Thanks for all the info so far. Any other info, please chime in.
 
I belive the Center to Center is 13 3/4"
The top piece pictured is the outside driverside.
Then the inside driverside.
Then the inside pass side.
And, u guessed it, the outside pass side.

CAM00130.jpg
 
Thanks for the visual! I'm starting to think, in this order:

- forget the entire project, it's not what I was looking for.
- swap the whole K
- use a plate
 
id just swap the k, it would really be the easiest, espeicially since there already is no engine or trans in the car, just pull the tires, pop the upper ball joints, pull the shocks, undo brakes, undo the steering, put a jack under the middle of the k and undo the 4 bolts
 
I'm starting to think that is best. Honestly, I'm leaning strongly toward not even bothering with the car, only because the entire point of this was to be a quick project, and it's turning into more than what I was planning. Do-able, yes. But what I was really looking for with all the other projects I have going on... no. I'll sleep on it. Some projects just weren't meant to be. I will have an FMJ again one day though.
 
I will read up a bit more on the FMJ front suspensions though, to see what all is involved (thank you for the quick summary though, Mr.Lopar!). I'm far more familiar with A-bodies, I really don't know much about FMJ.
 
not too much different. just instead of longitudinal torsion bars and strut rods, they have transverse torsion bars that are on the front of the k and go to each control arm and hold the lower control arms in place like the strut rods do on an a-body. also the FJMs have k-frame iso pads between the frame rails and k-frame that like to dry rot and deteriorate over time, but you can either get new poly pads or aluminum pucks. I have a set of the aluminum pucks in my 5th ave and have no complaints
 
If you're interested, I have a v-8 k-frame from a 80' mirada in akron ohio. Shipping would be a few hundred bucks I guess. Send me a private message. P.S. All projects seem to cost more, and take longer than you think! lol.
 
Oh yeah, I'm very well aware of project scope creep! Like I said, this particular one is just turning into more than what I was bargaining for as a whole compared to just dropping in a new engine. There are already other parts missing that I was counting on being there. I already have two projects going.
 
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72Dodge said:
I'm starting to think that is best. Honestly, I'm leaning strongly toward not even bothering with the car, only because the entire point of this was to be a quick project, and it's turning into more than what I was planning. Do-able, yes. But what I was really looking for with all the other projects I have going on... no. I'll sleep on it. Some projects just weren't meant to be. I will have an FMJ again one day though.
Click to expand...

4bolts on the crossmember, there was one on here for $100 complete w/brakes,steering box, etc.. The motors already gone, more than half the works done. The swapability of parts makes this easy as pie. You already have the 8 1/4 rearend (over the 7 1/4), do you have a drive shaft? Could be better, could be worse. Just a suggestion, if you're going to pass on it, why not pass the info to someone that might want the car. I have everything you'd need to do the project, however shipping would be prohibitive. These parts are easy to find. Try finding the chrome strip that goes on the passenger fender on an '81 Imp.
 
The decision has been made, I'm passing on the car. I understand that it's a do-able project, but like I said, it's not what I was looking for once I found out more about it. I already have two projects going, and I was looking for something I could just drop the engine/trans in and go. I could do the rest, but don't have time to mess with more anytime soon. (and no, he doesn't have the driveshaft, at least not the one that was originally in the car, so that was another item to find/cut/modify).

BUT... I think it's a great deal on a great car. It's been posted on here, but here is the link to FABO with more pics. I won't say what I had the owner negotiated down to on price, I'll leave that up to him, but at the price we were talking, I think it's a GREAT deal for someone. I hope someone can save this car, or at least part it out to save other cars.

THANK YOU to everyone for the education! I will have another FMJ some day, and if I didn't have so much going on right now, this one could have been it.

http://www.forabodiesonly.com/mopar/showthread.php?t=253789&highlight=mirada
 
Do a search on ebay for 340 motor mounts. I bought a set for installing in a street rod. Nice pieces if they are still on there!!
 
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