66 Coronet rear leaf conversion to four link?

[TC Sherman]

Hello B Body family!

So, I have a 66 Coronet convertible and am considering replacing the OE rear leaf spring suspension with a 4 link system. I want to do this for two main reasons. 1) update the 50 plus year suspension from it '66 tired materials and 2) hope to gain more tire space for the rear tires/wheels.

The goal is to build a street muscle cruiser with a newly built 440 dual quad with expected HP 500+ and has the 8 3/4 rear in it currently.

Has anyone else done this conversion (or similar)? And if so did you gain reasonable wider tire clearance when doing it? Any other challenges or reasons not to do the conversion? TIA!

 

[AR67GTX]

You will have to tub the rear wheel housings also before going much larger on tire, won’t you?

 

[Budnicks]

You really should go to the Welcome Wagon & introduce yourself 1st
maybe share a few photos or stories/history about the car or yourself

those car even when you mini tub them
they still don't have a lot of room for fat tires

A lot depends on your 'fab skills'
what tools you have & your knowledge
do you want some mostly bolt-in deal ?
or full on fab'd rear half ?

Ride-tech makes a decent one, (I know for later B-bodies) triangulated,
either coil-over or airwave shocks
still some welding of tabs on the axle housing, mostly bolt in
to where the leafs were

So does QA1, a lot more welding & cutting involved
some trunk floor & tin work will need to be done

in either setup you will need an upper shock mount
stock one sucks & will be too weak, to support the weight of the car
& a forward crossmember/safety loop (opt.) to hold the front of the bars
if you go with a traditional "real 4 link"
you will need a track bar (or Watts linkage, alot more fab) or locater
to keep the rear axle centered/side loads of some sort,
if it's not a triangulated style '4 link'

your biggest hurdle will be the OE inner wheel-tubs,
outer part has a hump inside/trunk floor that needs to be removed
& the inner part would need to move in toward the center,
to the side of the frame/flush at min., add the 2-3" splice down the center
that involve a lot more cutting & welding

street driving you may want to go to a poly bushing
racing a double adjustable a left & a right in each bar, Heim joint, 3/4" (5/8" min)
a lot more fab work

Chassis Engineering great examples of real 4 link
& rear half's bars frame parts rod ends

https://www.chassisengineering.com/product-category/four-links/

 

[TC Sherman]

You really should go to the Welcome Wagon & introduce yourself 1st
maybe share a few photos or stories/history about the car or yourself

those car even when you mini tub them
they still don't have a lot of room for fat tires

A lot depends on your 'fab skills'
what tools you have & your knowledge
do you want some mostly bolt-in deal ?
or full on fab'd rear half ?

Ride-tech makes a decent one, (I know for later B-bodies) triangulated,
either coil-over or airwave shocks
still some welding of tabs on the axle housing, mostly bolt in
to where the leafs were

So does QA1, a lot more welding & cutting involved
some trunk floor & tin work will need to be done

in either setup you will need an upper shock mount
stock one sucks & will be too weak, to support the weight of the car
& a forward crossmember/safety loop (opt.) to hold the front of the bars
if you go with a traditional "real 4 link"
you will need a track bar (or Watts linkage, alot more fab) or locater
to keep the rear axle centered/side loads of some sort,
if it's not a triangulated style '4 link'

your biggest hurdle will be the OE inner wheel-tubs,
outer part has a hump inside/trunk floor that needs to be removed
& the inner part would need to move in toward the center,
to the side of the frame/flush at min., add the 2-3" splice down the center
that involve a lot more cutting & welding

street driving you may want to go to a poly bushing
racing a double adjustable a left & a right in each bar, Heim joint, 3/4" (5/8" min)
a lot more fab work

Chassis Engineering great examples of real 4 link
& rear half's bars frame parts rod ends

http://[URL]https://www.chassisengineering.com/product-category/four-links/

[/URL]

Thanks. That is great information. I will introduce myself in the Welcome Wagon section.

 

[Dave6T4]

Will have to do a lot of strengthening of "flexy flyer" convertible body.

 

[Cranky]

Yeah, verts are not exactly very stiff plus the rear wheel wells, like has already been said are not very big and even with a 4 link system, you are limited on tire size. I know because I've had both.....