I see this is an older post but I am looking at the same issue for my 64 CS. Nothing has been done to the frame to strengthen it. The car is a weekend cruiser but it does has an LS with a 4L60 and it is fun to enjoy a "little bit" of that git up and go once in a while! Has anyone done much work on stiffing up these frames? I remember seeing an episode on Power Nation TV where they beefed up a 61 Impala frame. I would like to do 4 wheel disc brakes, run the exhaust out the back, and replace the body mounts at the same time.
Your frame is fine until you hit about 500 HP and go drag racing. There are lots of people seriously drag racing these frames without adding frame reinforcement.
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63 Parisienne sport coupe (The Big GTO), black, maroon interior, 409 4 speed; former owner of a 59 El Camino, 63 Corvette SWC, 62 Chev Bel Air SC. 1963- Pontiac top selling car in Canada
Mahone Bay, NS Still not old enough to need an automatic
We had an interesting discussion at coffee the other night. Us 65 and up B body owners worry about rusty frames. It seems the 64 and older X frame B bodies don't have that issue. It had never occurred to me before that body rust is the biggest worry on those cars vs. frame rust.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
In the video that Carl posted above with the '60 Bel Air hardtop (rare car!), it looks more like soft rear suspension complying to torque reaction rather than frame flexing. Is that true? I would think if the frame flexed that much the body would be popping open doors and trunk and twisting, especially on a hardtop body which would be torsionally weak by design. The video shows none of that, only the body leaning over as the rear springs compress on the right side.
I've seen them practically encase the X-frames in plate steel on those hopping lowriders, but realistically don't recall any huge reinforcements being necessary on X-frame drag cars or NASCARs back in the day.