[Gearheadfmc]

So, I have the old 1965 Fastback stripped of its "falling apart" suspension. Have a bare chassis outside and inside.

On the floor pan, I have replaced a 3" (front to back) x 8" (side to tunnel) piece on the driver side and a 3" x 4" on the passenger side. The floor and frame are solid with key dimensions measuring in specification ( I used this dwg found on the net, disregard the RED, as is not my dims.). Next step is to clean up the bottom, protect and paint. I'll have the car mounted on the front bumper frame mounts and rear Leaf Spring mounts and balanced on the rotisserie. Question is...

1. Can I install sub-frame connectors while the uni-body is on the rotisserie rotated 90 degrees?
2. Can I weld in front Torque Boxes while the uni-body is on the rotisserie rotated 90 degrees?

Am I just asking for trouble? Should I wait another 3 months until my suspension arrives and is installed?

Any opinions are well appreciated! TIA

 

[Redneckgearhead]

You want the car level and we'll supported. I would NOT recommend doing it on a rotisserie. While you're in that deep you might consider adding convertible inner rockers as well.

 

[66Ccode]

I don’t see an issue with that as long as it‘s in good shape.. That’s when I did mine.

 

[Huntingky]

I did mine on the rotisserie. NOW, I had already installed torque boxes and replaced cowl, firewall and patched floors so it was very solid. I made some measurements level and at 90 degrees and there was zero flexing. As long as you don't have the hundreds of pounds of engine, transmission and rear end weight on them, the bodies are very rigid.

 

[Gearheadfmc]

I did mine on the rotisserie. NOW, I had already installed torque boxes and replaced cowl, firewall and patched floors so it was very solid. I made some measurements level and at 90 degrees and there was zero flexing. As long as you don't have the hundreds of pounds of engine, transmission and rear end weight on them, the bodies are very rigid.

Really, this chassis is solid. I have it on jack stands now an it is on a concrete pad with built-in slope for water drainage. basically, only 3 of the 4 jacks are carrying the load.

 

[Jeffncs]

I just finished rockers, torque boxes, floors in my 65 vert. The car was already on jack stands sitting on a level concrete floor. I installed each subframe connector as I finished the job on that side.

Both sides are basically done except for a few welds to grind down. The car sits flat and rock solid as a completed assembly. Front end work start now that the car is structurally complete.

Im happy. Does that make it right or the best? Don’t care! Worked out well for me! …except for trimming the floor reinforcement pans and welding on my back. That was terrible!! Haha

 

[Gearheadfmc]

I tend to believe as you believe! Thanks

 

[Woodchuck]

Torque boxes? Sure. Convertible inner rockers? Absolutely. Convertible seat riser? You bet. Subframe connectors? Wouldn't install them at zero degrees.

 

[Gearheadfmc]

You want the car level and we'll supported. I would NOT recommend doing it on a rotisserie. While you're in that deep you might consider adding convertible inner rockers as well.

Good call! The area of the floor is a small patch next to the frame rail. So, I'm going to install the inner rockers. 2 Inner rocker, 1pc floor pan and Lower reinforcement plate Ordered!

 

[Gearheadfmc]

I just finished rockers, torque boxes, floors in my 65 vert. The car was already on jack stands sitting on a level concrete floor. I installed each subframe connector as I finished the job on that side.

Both sides are basically done except for a few welds to grind down. The car sits flat and rock solid as a completed assembly. Front end work start now that the car is structurally complete.

Im happy. Does that make it right or the best? Don’t care! Worked out well for me! …except for trimming the floor reinforcement pans and welding on my back. That was terrible!! Haha

Curious.... if you installed the inner rocker and torque boxes, why do you need the subframe connectors? I thought the inner rocker did that job...

 

[Redneckgearhead]

Curious.... if you installed the inner rocker and torque boxes, why do you need the subframe connectors? I thought the inner rocker did that job...

Imo, as this is a debatable issue, adding sfc helps stiffen things up by taking a large square, your rockers and frame rails, and turn them into two smaller boxes. Am I right? Who knows , I added both as I was there and had both convert inner and tin man sfc. An added benefit to my sfc was I didn't need to add the antitrust tubes to my floor supports when I bolted in my trans crossmember.

 

[Jeffncs]

Here’s my short story…

I bought a rusty POS that needed Torque boxes…. Well it turned out that the rockers, floors and both front torque boxes were shot along with 1 rear torque box. (I shouldn’t have been surprised!!)

Plan for the car: 90% street car with some red light racing behind a mildly built 351w and toploader.

Note - doors remained on the car to verify alignment. Engine and full driveline were removed to eliminate all weight from vehicle.

Note 2: I did one side at a time.

As I started cutting and bleeding on this thing, I made the decision to go all the way with structural rigidity. I already had to do the rockers, floors, torque boxes, etc. - the SFCs were the logical final step. When I had all the rusty stuff out of the way, I cut the rear of the front frame rail off for the square SFC to fit inside. Once all the new steel was welded in place, I trimmed the floor reinforcement pans (front to back) for a tight fit of the square tube-shaped SFC sides to the floor reinforcement panel.

Happy with the fit, I plug welded the front of the SFC to the front frame rail, solid welded the inner and outer seams of the SFC to the floor reinforcement panel and finally welded the rear of the SFC to the rear torque box.

This was all done with the body supported by 8 screw jacks to keep the body perfectly aligned (4 per side with a floor jack stepping in occasionally to help). Doors stayed on the car to confirm alignment.

Final product is a rock solid car with nicely aligned doors, zero sag. I’m still working on panels, so the engine sits on its stand and the toploader is waiting for some replacement parts before final assembly into a rebuilt unit.

I’m pleased with the way things turned out.

 

[Gearheadfmc]

Here’s my short story…

I bought a rusty POS that needed Torque boxes…. Well it turned out that the rockers, floors and both front torque boxes were shot along with 1 rear torque box. (I shouldn’t have been surprised!!)

Plan for the car: 90% street car with some red light racing behind a mildly built 351w and toploader.

Note - doors remained on the car to verify alignment. Engine and full driveline were removed to eliminate all weight from vehicle.

Note 2: I did one side at a time.

As I started cutting and bleeding on this thing, I made the decision to go all the way with structural rigidity. I already had to do the rockers, floors, torque boxes, etc. - the SFCs were the logical final step. When I had all the rusty stuff out of the way, I cut the rear of the front frame rail off for the square SFC to fit inside. Once all the new steel was welded in place, I trimmed the floor reinforcement pans (front to back) for a tight fit of the square tube-shaped SFC sides to the floor reinforcement panel.

Happy with the fit, I plug welded the front of the SFC to the front frame rail, solid welded the inner and outer seams of the SFC to the floor reinforcement panel and finally welded the rear of the SFC to the rear torque box.

This was all done with the body supported by 8 screw jacks to keep the body perfectly aligned (4 per side with a floor jack stepping in occasionally to help). Doors stayed on the car to confirm alignment.

Final product is a rock solid car with nicely aligned doors, zero sag. I’m still working on panels, so the engine sits on its stand and the toploader is waiting for some replacement parts before final assembly into a rebuilt unit.

I’m pleased with the way things turned out.

Thanks for the input Jeffncs....great story and info....I was thinking that by doing the inner rockers, I'd be good. Now, I'll have to rethink... or ... overthink..... or over-engineer...... maybe

 

[Redneckgearhead]

Gotta weigh the pros and cons, I see no cons by adding them, especially if you're that deep into it.

 

[Gearheadfmc]

Gotta weight the pros and cons, I see no cons by adding them, especially if you're that deep into it.

That's what I'm thinking.... What's another $400 at this point......

 

[Jeffncs]

I caught my SFCs on sale for ~$120 from CJs. Theyre not labeled, but came from SMR so decent quality. I’d almost wish they weren’t powder-coated though because I had to grind a lot of it off for welding…. JT I know they’re geared towards bolt-in installation with the option to weld-in instead.

Sub Frame Connector Bolt-On Pair Mustang Convertible 1965-1970

Pair of Bolt-On Style Sub Frame Connectors for 1965, 1966, 1967, 1968, 1969, and 1970 Convertible Mustangs.

www.cjponyparts.com

 

[Redneckgearhead]

Tin man sells them on summit racing for 200$.

 

[wicked93gs]

I installed torque boxes and subframe connectors with the car sitting on all 4 wheels before going on the rotisserie(although I will qualify that with the fact that I lifted the car 2 feet in the air and had it sitting on "blocks" under each wheel with chocks). I couldn't say whether there is any danger of things flexing out of place on the rotisserie sitting sideways, but I would do my best to avoid it. I did finish tying my SFCs to the floor the entire way with the car on the rotisserie, but initial basic install was done with the wheels sitting on the ground. Torque boxes were done sitting on the ground as well(why not? its easy enough to do, especially if you are replacing the front floor extensions at the same time). However, the torque box welds that were underneath the car I just tacked in place then finished welding them with the car on the rotisserie(no reason to fight welding upside down if you don't have to)

I actually technically have 2 sets of SFCs installed on my car. I have the global west tubular SFCs because they are DOM tubing...but I was not satisfied with those alone, so I bought a set of USCT contoured SFCs:


These tie in to the floor pans the entire way...but they aren't tubular DOM. So I combined the two sets, I installed the global west SFCs, and then cut up the USCT SFCs and welded the sides to the global west SFCs, the result is that I now have tubular DOM SFCs that tie into the floor the entire way that in cross-section look something like a figure 8:

I probably went overboard with the idea, but I missed the opportunity to do convertible rockers at that point so I was making up for as best I could.

 

[Israel]

Start a Build Thread, I'd like to follow the work.

 

[Gearheadfmc]

Well... thanks for all of the input. Torque Boxes and sub-frame connectors will be it. Torque boxes on the Rot, Connectors on the ground first for tacking, then final welding on the Rot.