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78 BB to 79 Suspension Swap

Night Runner

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I have a 78 BB car that is used for parts. So far I have yet to use any of them, so its still a complete car, but I was planning to remove the K member and front suspension, rebuild and swap to my 79 that I am having painted right now. I assume the motor mount locations would be the same from the BB to SB K member since my 69 swapped just fine, but does anyone know for sure. I am also having a suspension shop make customs uppers and lowers to convert it all over to coil over and get rid of the torsion bars and weak stock control arms. I completely rebuilt all of the suspension on the 79 in 06 with the best thing PST had to offer and have had some sort of pop or squeak ever since. I upgraded the front sway bar and it doesnt really fit all that great and I am tired of the front end sounding like it is all original and still 33 years old. I replaced everything that moves and more and was disappointed with the outcome so I have decided to try again with the 78 BB parts.
I think this may be a step up since it was a BB car and rear end has a sway bar that mine does not have, but worst case would be all new again and hopefully sound better. I know its a 4000 pound car that I will never hit a road course with, but it would be nice to take a tight overpass at the speed limit or a little over. :) The shop that will be building the control arms is going to make the brackets needed to adapt to the frame rail so I can drop the torsion bar and the cross bar that keeps the LCA in place. This will give me alot of adjustment as far as right height and alignment.

Has anyone swapped a BB K member into a SB car without adding the BB, and would the 78 to 79 thing be a problem. From what I can see and quick measurements it all looks the same to me.
 
the only difference with the small block cordobas and the big block cordoba are the motor mounts/radiators,exhaust and the torsion bars. the K members are identical. front sway bars came on every cordoba. a buddy of mine literally has a farm of cordobas and every one of them ,big and small block, have front and rear sway bars, and the same exact front suspensions, and K members. the 400 cordobas have fatter torsion bars . every one of them have 11" drums as well. so unless it is coincidence, (he has 13 at last count + 2 magnums) and unless someone has pics showing otherwise, i stand firm on this. i have yet to see a cordoba that did not have a rear sway bar at some point in its life.
 
73-78 B-bodies have different K-frames for Big and Small Block. Their difference is the motor mount locations.

You cannot put a big block in a small block k-frame unless you use Schumacher conversion mounts (and modify the K-frame a little) or want to weld on new mounts.

I know this for Fact because Rumblefish360 put a big block into his small block 79 Magnum and he showed me every nuance (in person, at his house).
 
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My 79 does not have a rear sway bar and never has. This car was bought new in 79 by my grandparents and driven 21k miles in 17 years before I bought it.
So basically I am either going to have to do some fab work to mount my 360 in the 400 frame or scratch the whole idea. That sucks.

Thanks for help guys. Would have sucked to get everything off and have problems putting it all back together.
 
we put a 400 in a 360 77 cordoba using all factory parts with no modifications or special mounts. so it would have to be something to do with the 79 k member. for years people kept saying you have to change the k frame when going from LA to B/RB or visa-versa in the 66-72 B bodies when you dont.
 
Yeah I dropped a running 318 in my 69 charger that was a factory 383 car with no mods to anything. I thought this might be along the same lines.
 
Yeah I dropped a running 318 in my 69 charger that was a factory 383 car with no mods to anything. I thought this might be along the same lines.
i should be going out to the "farm" in the next few days . i will measure the 79 sb k member versus the 75-78 bb and we will find out for sure, i am almost positive they are the same , but i could be wrong. but like i said, we put a BB in a SB 77 doba and it was a direct swap. i just dont see any reason they would change them. they have always been the same in previous years with the exception of the slant 6.
 
A few years ago I took a K frame from an older cordoba and put it in a 79 St Regis. I then installed a 440 into the St Regis. All direct bolt in. But try Schumacher they may have mounts that will work without changing the K frame.
 
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