Gents, i'm starting to think of winter projects for the 66. What are the chassis bracing choices out there that can be installed without removing the body from frame? Bolt-on or weld-on works since I won't be at a point where I can remove the body (by then I may just box the frame). I know about rear UCA/LCA connector which i'm planning to get but does anything else come to mind?

Last I spoke with Mark at SC&C, he said he was putting together a book about chassis cage design and overall chassis stiffening. I don't think that book is out yet.

From all my research and everything, no there isn't anything really bolt on like they make for Camaro's and such. The only thing that comes to mind is Air Ride Technologies makes a bolt-in roll cage that would help stiffening things up. You could also swap your rubber body mounts for polyurethane ones.

Furthermore from everything I read, nothing will really stiffen it unless you go vertical. Meaning if you just stiffeners in the frame, since its still just a horizontal machine, its still prone to twisting. Adding that hoop of a roll cage really stiffens it up, since it makes a box out of the frame. I don't know if that makes sense to you though.

Hope this helps.

vertical is best, but horizontal still works. think of a sway bar. the bars need to be large to accomplish this and there is added weight, but they do help. crossmembers also help alot. when i added the watts cross and my mid cross it stiffened the frame a lot.

It sounds like there aren't too many off-the-shelf options which is what I was expecting unfortunately but still ok.

What are your thoughts on a standard cross member versus an x-member brace? I don't have an engineering background but i'm curious to not only the horizontal and vertical loads but also the lateral shear stiffness (yaw) as well. I'm thinking an x-member of some sort would be best for that.

I'll have to put the car on the hoist sometime soon to get some ideas. Not even sure if it's possible without having to jump through hoops around the driveshaft and exhaust.

I know someone will say... "just do a frame off, box the frame, and be done with it." Well, I'm just brainstorming :thumbsup:

Boxing the frame and welding up the seams between the GM welds helps quite a bit. It's hard to get bracing in the car that is effective without cutting/going through floorpans and such. Roll cage would be the most effective but not the best for street use.

btw.. Tim & Tim, we're all in socal and I see you're both pretty close to being done. Hopefully we can plan a meet & drive sometime soon! Both of your cars are on my top 5 favs on here.

Boxing the frame and welding up the seams between the GM welds helps quite a bit. It's hard to get bracing in the car that is effective without cutting/going through floorpans and such. Roll cage would be the most effective but not the best for street use.

I recall seeing a pre-cut boxing kit fior the "C"'d portion of the frame. I don't recall the specifics ( thickness, etc).

One thing that comes to mind, BEFORE any welding, I'd make sure the frame is straight and not already tweaked from age, etc...