55 & 57 chevy frames

[mikes55]

I installed a 57 chevy frame to where I had back halfed my pro street 55. I know the one difference was the bumber horns which I redid to accept the 55 bumpers but I am having problems with the clutch setting not being able to get enough free play. is the pivot ball bracket location different from a 55 to a 57. I have made patterns off of a friends 55 chassis using the lever for the column shift and the oval hole and the small hole in the chassis and they are different from a 55 to a 57. Planning on converting the z bar to 57 and I am using bracket for aluminum bellhousing which I won't have to straighten out but also notice the only other part different is the clutch pedal push rod is different from a 55 it looks longer. trying to make patterns off of both to see if I have pivot ball bracket on frame in correct place. anyone know the difference in both frames in clutch area. would appreciate any help.

[Rick_L]

The frames should be the same in that area except that the diameter of the pivot ball itself may be different.

You can double check using the frame dimensions in the assembly manuals which are online.

The linkage is different between the two. The legs on the z-bar are clocked differently. Should not be a problem if you use all the pieces for one year. 57 is preferred because of the better clutch fork.

[mikes55]

that's what I am using. any other diagram beside manual to determine placement of pivot ball bracket on chassis?

[NickP]

Not certain there would be anything more accurate than the actual build prints.

[mikes55]

they are so hard to read and understand

[Rick_L]

Are you using online versions or printed versions of the assembly manual? My experience is that the printed drawings are clearer, but the computer stuff allows you to zoom in - so a combination of the two may be what works best.

[mikes55]

i looked at both. i was using the bracket on the frame for the column shift, the oval hole, and the 1/4 hole next to it for the pattern. do you know if the bracket for the column shift is in a different location for the automatic and standard shift.

[Rick_L]

I believe the bracket for the automatic transmission linkage is in a different spot from the clutch linkage z-bar pivot ball bracket.

[Gmvette]

My 57 nomad was originally an automatic transmission. The original frame had the ball mount welded to the frame for standard shift Z arm for the clutch. I don’t know if they are all like this or not. I used this along with the ball stud threads in the side of the BBC block to insure engine position was good. In my case a modified 55 chevy Z arm (i think as I purchased it used) was modified to change one of the arms to complement the custom link arm I made to make the depressing of clutch smoother and easier on my leg. Made arm longer and changed position on one only. I think the ball studs, fork, bell housing, and lower rod were Corvette pieces.

You shouldn’t have to go thru all that I did unless you want to alter the motion.

[Rick_L]

gmvette, I hate to have to call out on things like this, but just about everything you posted is false. Period.

[BamaNomad]

I've never seen an original frame with brackets/mounts for both auto trans shift and manual trans clutch. The factory seems to have done either one or the other, depending on what the car was specified for.

gmvette: I suspect your frame was swapped from another car and the required mount added by the owner at the time...

[Gmvette]

I've never seen an original frame with brackets/mounts for both auto trans shift and manual trans clutch. The factory seems to have done either one or the other, depending on what the car was specified for.

gmvette: I suspect your frame was swapped from another car and the required mount added by the owner at the time...


No It does not have both. The rear tranny hanging mounts and linkage mount are not there. Definitely shows sign if you look close they were cut off. The automatic taken out was not the original 57 type. It was a Chrysler with an adaptor plate. But that wasn’t the topic of discussion so I didn’t mention it. The welded on brace for the clutch shaft was there. Original or not can’t say. But the position was right for the Z shaft to align with the ball studs threaded hole in the BBC.

[Gmvette]

gmvette, I hate to have to call out on things like this, but just about everything you posted is false. Period.


Well this is the list of parts bell housing is 621 for 67 corvette, the clutch fork is 532751 64-67 (tel:532751 64-67) corvette from Corvette Central, rod is 3872960, stud in block 3752863, stud from Corvette Central #532739 also 64-67 vette.

The Z arm as I said was swap meet and only thought to be 55. May be not but irrelevant since as I said I changed the arm anyway. As for the automatic tranny the rear side mount were removed. The tranny, was a Chrysler push button was a rear tail shaft mount. But that is also irrelevant to discussion.

Now if you don’t believe the action is comfortable to use and the pieces I use were mostly Corvette parts then so be it. I know my car fairly well as I did all the work. I tried to attach photo but not sure it shows much

[Al_Dente]

My 57 nomad was originally an automatic transmission. The original frame had the ball mount welded to the frame for standard shift Z arm for the clutch. I don’t know if they are all like this or not...The folowing Nomad owner says, the '57 frames were last production year oddballs:


https://www.youtube.com/watch?v=p_kDIBsVxzs

[HILLBILLY823]

The assembly 57manual gives a dimension from an imaginary line to the frame ball pivot. There is also a vertical dimension from this line to the lower steering box hole in the frame. Subtract the difference and you have the vertical dimension from the lower steering box hole to the ball pivot stud. Likewise there is a dimension from a tooling hole in the frame back to the pivot ball and a dimension from the tooling hole back to lower steering box hole. Once again subtract the difference and you have a "fore and aft" dimension from the lower steering box hole to the pivot stud.

[markm]

Why would anyone go to the effort and expense of adapting a Dorkflight to a BBC. The Slowpar guys I know are jealous of the Alum PG and TH400 options available to Chevy guys.