1970-1972 Chevelle frame...what will get me bounced?
 

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Re: 1970-1972 Chevelle frame...what will get me bounced?
 

If your year had F35 HD frame available as an option, it is the convertible frame, adds about 40 lb but will give you a tremendous increase in stiffness.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

secret :0

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Any GM midsize convertible frame (buick/cutlass/lemans/gto) of the same years had boxed frames extra support in the rear kick up area etc.---all the others were C frames the Conv also had more body fastening points for frame to body stiffining

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

secret :0

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

The El Camino and the wagon use the same wheelbase frame,but the wagon is a C cross section.I seem to remember some El Caminos have a boxed frame.The 4 door, the wagon,and the EC are a longer wheelbase than the 2 dr.hardtop and the convertible.There's just enough differences to really screw you up if you don't catch them!The 68-72 2 dr hardtop all use the same frame, so there are 5 years of similarities here.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Greg, thank you...

Jason

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Camino has the boxed frame ---WAGONS DO NOT they have the C frame

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

secret :0

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

2011 NHRA rulebook section 10A page 8 says frame must be stock for body used so I'll check to see if GM had a HD frame for the 2 door HT yers is a HT correct???

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

secret :0

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

secret :0

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

you better get ahold of NHRA and ask them FIRST---I see your point but after checking NO HD frame was offered this is the breakdown
Same frame part # for 68-72 --2 dr HT or conv
Tempest
F-85
Chevelle
Skylark--Not Grand Sport or 455 engine

however there are additional braces and mounting points for Conv vs. a HT
I doubt if NHRA checks frames but "if" there are mods you might be in trouble--See if ya can find a Conv from one of the above cars and see if the frame is boxed or a C that will tell ya right off the bat

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

secret :0

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

What does it matter? You can box a "C" frame and whatever else you want to do to your hearts desire. It's no different than running an extra mile of roll bar tubbing. If that's what you think will help, it's OK.
Now lightening the frame would be another matter all together.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Now, that's what I need to hear! Thanks Jeff.

I assumed I could do pretty much anything but, until I hear from Travis I won't know...

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

I have a pair of boxed frame sections taken from an El Camino.
Pm me if your interested.
Greg

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Sorry, but why is it everybody has to get an opinion direct from tech on every issue? NHRA makes a rulebook and it's free. You have to read it, learn it, and follow it. Every little detail can not be put into print. It's a guide that has the most important elements and from there you make the decisions.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

the convertible frame merely added V shaped boxing sections to the open C channels between the torque boxes. Up through 67, the open C behind the rear wheels was also boxed part way. All body mount areas are on the main frame, nothing added there by the boxing sections. All A body frames were boxed at the front bumper back to the front torque box, and from the rear torque box over the wheels to the body mount area behind the rear wheels, so nothing was added there either by the convertible frame modification. a shorter transmission cross member was used with convertibles because they didn't go into a c section. Up through 67, there were "ears" welded to the inside verticals of the box, and 68-72 the boxing section included a formed perch for the cross member.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

El Caminos had the convertible frame, but after about 1967 they had a longer wheelbase than the 112" used by 2 door cars. Olds Vista Cruisers had boxed frames, but longer wheelbase. I have heard that the Buick GS's had boxed frames, but haven't checked. That could be why the list above separated them from other cars. Olds offered F35 through 1970. I don't know about other divisions; should be a list of options in the chassis section of the parts manual, at the front.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

i don't see how it's be any different than subframe connectors BUT i don't make the rules...



jeff,wanna send me one of those "free" rulebooks?
(must be a west coast book)..;)

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

If I had unlimited money to abuse the rulebook like I would like to then, I wouldn't have asked a soul about this frame question...I just don't want to be the guy who gets tossed after building a caged car just to cut it apart.. ya know...

Thanks for the advise.

Jason

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

It's free, it's online and it's at www.nhra.com

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Maybe I'm missing something, but it looks like the rule book is 10.00 + shipping.......

http://store.nhra.com/products/nhra-2010-rulebook/

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

yeah, even the "free" downloadable one wants you to give them your membership number

http://www.nhra.com/members/registration.aspx

i guess i can wait a couple of weeks and pick one up at bandimere's swap meet space in feb...

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

I guess I always assumed those building or owning a class car were NHRA or IHRA members and had access to a rulebook :confused:. My bad but that sure explains a lot!

Here is the link and as Tom pointed out, you will need to be a member. You can then download your own copy which is free with membership.
http://www.nhra.com/members/benefits.aspx

So to those out there contemplating owning or driving a class car, I strongly suggest becoming a member, knowing the rulebook, subscribing to Nitro Joes Stats and going to your local class race and talking to the participants.

Merry Christmas to all!

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

just so ya know, i DO pick one up every year but i still have questions...
i've found a few things, while not in the rule book,won't pass tech

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Jason You have a Pm

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

The Buick GS cars are supposed to have extra bracing in the rear of the frames. They also had a support bracket that went from the frame to the mounts for the lower control arms.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

is that the same ones that tie the upper and lower control arm mounts together?
that was a factory deal for ALL A bodys.
must be a reason for 'em cuz just about every chevelle/montecarlo/elcamino i've ever owned (a bunch) had 'em..

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

Edelbrock & hotchkiss perf supposedly made/make some triangular stiffening plates that helped stiffen the frames on 454/455 engined cars---Supposedly all 454/455 used the A body convertible boxed frames whereas a sedan or 2dr ht used the standard C or non boxed frames

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

<So to those out there contemplating owning or driving a class car, I strongly suggest becoming a member, knowing the rulebook, subscribing to Nitro Joes Stats and going to your local class race and talking to the participants. >

The last ND I received before the holidays had an ad in it for the printed rule
book for $7.00 + handling charge if you called in the order. If you do it on
line then it is $10.00 + handling charge.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

These were a single strut that went from the front lower control arm bolt to the frame. My buddy's '70 Stage 1 car had them, my small block Skylark did not.

I do not recall seeing anything that tied the top and bottom mounts though. I have not been under my Buick for a while though.

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

This is what the GM "A" body rear upper, and lower ca braces look like.....
http://www.musclecarmetal.com/catalo...er.asp?id=1552
They did not come on all "A" body cars, just the 4-speed, or big block, or cars with the "hi- performance suspension option......

Re: 1970-1972 Chevelle frame...what will get me bounced?
 

yep, that's the ones BUT my wifes old 68 300 chevelle had 'em...but you're correct, not ALL A bodies had 'em.
seldom seen them on 64-67's.
was there a TSB for them somewhere back then?
i dunno.
heard it was a retrofit kinda deal for some issue back then and it just went into assembly line cars...

60K 6 cyl/3speed...bought it from the original owner..