gear head

Has anybody ever used these…
http://www.swracecars.com/store/64-72-CHEVELLE-GTO-442-CUTLASS-SKYLARK-COIL-SPRING-SW-DIRECT-FIT-REAR-FRAME-RAILS-OSCARItem_441=10-006.aspx

My fame is weak and thin in the back end so I plan on rebuilding the rear frame, boxing and bracing the rest of chassis this winter. These would save a quite a bit of time compared to fabricating new rails however, In the pictures I’ve seen of their other fame rails they are buckled on the inside radius.

Just curious if anyone has used these and what their thoughts were once they had them in their hand.

Thoughts?

Thanks,
Josh

2blu442

Josh, I'm not familiar with these products. But if you want to replace rotten pieces with factory parts you might post a parts wanted thread. I've got several hardtop frames and suspect there's other members who've got frames they could sell or cut portions out of.

John

joe_padavano

These are for narrowing the rear end, not stock replacement of rusted rails.

gear head

Thanks for the replies.

I guess I should have been more specific in the post..

It is my intention to move the frame rails inward a bit and use a mini tub. I realise you can fit a decent tire under the factory configuration but, I want to fit more meat under the rear, not necessarily steamrollers.

John,

I have thought about using factory rails, stepping them in then building torque boxes around the tie in point. I think that this option might be a bit more money after I figure in time, consumables and the extra steel.


Joe,

I know these are not OEM replacements and that's why I am looking at picking them up.

joe_padavano

Got it. Sorry, I didn't pick up on that from the original post.

507OLDS

I haven't seen these rails,but Wild Rides makes a nice rear crossmember,to replace the one over the axle.
You can go to a performance G-body site,and look at how some of those guys narrowed their existing frame rails,to fit bigger tires.You can use that same concept for the A-body frames.There was a magazine article some years back,where they did it for a 70 GSX pro-street project.
Don't feel bad that your frame is weak.Even the perfect rust-free ones are.They were barely made to handle the power back then,let alone the car itself.

joe_padavano

Sorry, but as a structural engineer, I'll say that this is not a good idea. The up-down bending stiffness in the frame rails comes from the top and bottom caps. Removing this material reduces that stiffness in direct proportion. Cut the frame rail in half and up-down bending stiffness will be about half that of the original rails. Similarly, torsional stiffness comes from the cross section of the frame rail. Narrowing the rail similarly reduces this stiffness.

Moving the rails inward is the far better method of gaining tire clearance.

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507OLDS

I guess I should clarify to look at the ones done correctly,that added structural supports. Not some hack like a kid would do.

gear head

No worries, I sometimes have a bad habbit of thinking people can read my mind.

Thanks for the tip on Wild Rides, I like that crossmember. I've been looking around for a bit now to see what others are doing and have seen some good stuff as well as things that make me scratch my head in disbelief.

PS, nice to hear from an Erie boy...I grew up bouncing back and forth between Millcreek and Girard.

507OLDS

I lived in Millcreek,by the airport,my whole life,then moved to Girard 10 years ago.

gear head

haha, It sure is a small world.