Convertible frame question.

Jeff Olson

Well Known Member
Supporting Member 2
Thanks to the members here I am getting closer by the day to getting the '63 the transplants she so desperately needs. 409 rotating assembly, Jason (1961BelAir427) manual transmission parts for swap, Paul (pvs409) and Dave (Iowa 409 Guy) the dual quads and intake. Anyhoo, I digress. I am looking to get about 450 HP out of the W when all said and done and if a person would get a little carried away banging gears will the frame and body mounts take the twist? Without the additional stiffness provided by the solid roof will I need to beef up the frame? I searched the forum but didn't find anything that really addressed my question.
Hopefully I can sing along with the Beach Boys by fall or worst case early spring......
 

gwagon

Well Known Member
Your convertible frame has reinforcements welded to it from the factory and has two extra body mounts. Also the body has reinforcements on the bottom of the rocker panels that are not on hardtop cars. I don't have pictures but maybe someone has.
 

ROYALOAK62

Well Known Member
Supporting Member 1
On my 1st 1962 Impala conv. back 1963-67, I used to rev my 327 with a pg Trans all the time to street race. And I mean rev it up and just drop it in gear. The rear end will give out before most of anything else. The first thing that will show up concerning the body twist is a crack on the rear corner of the door jam. And it took years to show up.
The weakest point is the rear end & Axels shafts. Sure it wasn’t a 4-speed, but I sure beat the crap out of the car.

Dave
 

pvs409

Well Known Member
Supporting Member 11
The convertible frame will not flex (they have extensive plates welded to the top and bottom of the frame ). A Hardtop frame does not have these plates and has 8 body mounts vs convertibles that have 12 mounts with the 4 extra ones from the firewall to the rear axle.

P1000489.JPGDSCN7673.JPG


I agree the rear end will give out way before the frame. I considered a Ford inch but at close to $ 3000 for street driven cars I did not spend the $.

My 62 SS 409 stroker motor Hardtop and my 62 SS 409 stroker motor convertible have two upper control arms. girdles on the posi rear ends (I could add better rear axles). The hardtop has been down the 1/4 mile about 15/20 times (factory rear axles) -only posi girdles and the dual upper control arms (and not sidestepping the clutch when launching the car)

See my pictures above of my extra control arm on my 62 SS 409 convertible -one with factory upper arms and the first picture with
adjustable upper control arms
Paul
 

Jeff Olson

Well Known Member
Supporting Member 2
As always, the answers are here. All you gotta do is ask. :read

I looked at 9 inch Fords from Speedway Motors and others and I agree they would be much more stout but I don't plan to regularly abuse the car so thinking I will may stay with the factory rear. BUT, it is an open rear end so depending on how many $$ to change over I may change my mind.
 

ragtp66

Well Known Member
The convertible frame will not flex (they have extensive plates welded to the top and bottom of the frame ). A Hardtop frame does not have these plates and has 8 body mounts vs convertibles that have 12 mounts with the 4 extra ones from the firewall to the rear axle.

View attachment 62813View attachment 62814


I agree the rear end will give out way before the frame. I considered a Ford inch but at close to $ 3000 for street driven cars I did not spend the $.

My 62 SS 409 stroker motor Hardtop and my 62 SS 409 stroker motor convertible have two upper control arms. girdles on the posi rear ends (I could add better rear axles). The hardtop has been down the 1/4 mile about 15/20 times (factory rear axles) -only posi girdles and the dual upper control arms (and not sidestepping the clutch when launching the car)

See my pictures above of my extra control arm on my 62 SS 409 convertible -one with factory upper arms and the first picture with
adjustable upper control arms
Paul


Paul, I am curious to see where the additional plating is I know they had the extra mounts welded on for a convertible and I was pretty sure that all the Convertible and El Camino frames were made by Chevrolet not A.O. Smith or Budd. I also thought all the convertible and elcamino and possibly Sedan Delivery BODIES were assembled at Flint then trucked to their final assembly plant locations. I'm a 58 guy so I am not as familiar with the "late model" x frames. Correct me if I am wrong the Chevrolet built frames were 1 piece seamless, the A.O. Smith frames were C channel open on the inside and the Budd frames were a 2 piece welded boxed frame.

Chris
 

pvs409

Well Known Member
Supporting Member 11
Every 61 to 64 Chevy frame on the 10 cars I have restored were boxed welded frames with the frame sections behind the rear axle were C shaped frames.
First picture below is a 62 Impala Hardtop frame & the last picture # 7
2nd, 3rd, 4th, 5th, 6th pictures are a 62 Impala convertible frame -see the plates that start on the top(and bottom of the frame -can't see the bottom) of the frame just behind the front mounts. The plates start again just behind the X portion of the frame and run up the frame to just over the rear axle. note the extra raised section over the top of the rear axle as compared to picture # 7 of back of the 62 hardtop
Paul

62 SS Blue frame finished 001.jpgP1030157_tn.jpgP1030158_tn.jpgP1030156_tn.jpgP1030155_tn.jpgP1030154_tn.jpg62 SS Blue frame finished 002.jpg
 

303Radar

Well Known Member
Supporting Member 2
The frame on my '59 El Camino (built in Oakland) was two C channels overlayed to become a box. From just past the rear axle back, definitely not boxed.
The original welding looked like at least four different welders worked on it. Some welds were much better quality than others. But there was several 4 to 6 inch sections with no welding at all. My frame looked nearly identical to Paul's first and last pics.
One of the first things I did was I had the welds finished so the frame looked like it had one contiguous weld from front to past the rear axle.
Here is a link showing the pics of the finished welding:
http://www.348-409.com/forum/threads/ragans-59-el-camino-rebuild-project.27910/#post-245589
 

ragtp66

Well Known Member
Paul

Thanks for posting the pictures and the explanation. You are always an encyclopedia of information and willing to share it which is much appreciated. I wonder if its strictly a 61-64 thing or if any of the earlier cars had the same reinforcements? I have run across some 58's that have the two hole rear lower control arm mounting holes (lower for wagons) and some that have had only one hole but 3 of them were all A.O. Smith C channel frames.

Chris
 
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