Bolt Pattern Change on a 64 Catalina
 

has anyone changed the bolt pattern on the front of a 64 big car?
i have upgraded the front brakes to the MP Disk brake setup but still stuck with the 5x5 bolt pattern.
anyone ever redrilled a set of rotors to change the bolt pattern?

I like the 5X5. There are a lot of wheels in low prices in this pattern. If you want to nit pick its slightly stronger.. Every new wheel that's out comes in both 5x5 and 5x4.75.. Plus the 5x5 usually comes with 4" or more back space which is what you want with these wide track cars..
Wheel Vintiques makes some real nice chrome reverse wheels called Series 64 for your car.. They are some of the best new wheels I ever had.. Summit sells them.

Why do you want to change, is it so you can use wheels that have a different bolt pattern? It's been discussed here before but I don't know if anyone has actually done it. The suggestions I remember were mostly to have a machine shop redrill the hubs.

I did the "tall spindle" mod on my 68 GTO back in the day and thought I was pretty clever to snag the spindles off a Caprice wagon so I could get the bigger rotors. (Before I knew about the Camaro 1LE option).

Yes, I redrilled the Caprice 5x5 rotors to the A body standard 5x4.75. No issues.

I'd understand changing to a 5x4.75 bolt pattern if that gave you a brake upgrade but as you can get stacks of good wheels in 5x5 (and plenty of 15s-17s in B-body friendly widths/offsets) I don't understand what you'd gain from changing the PCD.

X 2.

the thought is to give myself more wheel options.
the last i checked on Jegs or Summit there were very limited 5x5 bolt patters in stock. this was a year or so ago. plus i would like to put some skinnies up front and when i checked on a narrow wheel in the 5x5 BP there was nothing smaller than a 6" width.

My 61 has the rear axles redrilled for 5x4.75 for a change to disc brakes. If the rear can be done the front can be done. But I would be sure a good machine shop did the work. It has to be well centered and spaced.

You didnt have to go to 4.75 inches to put on rear disc brakes. You can install a 5 inch kit.

You are right. But it was done by the previous owner. And long enough back in time that the kits available now were not available. His solution was to put C3 Corvette brakes on by using the Corvette front spindles/caliper/rotor assemblies. That made the change to 5x4.75 and forced a change to 15 inch wheels. At that point it was easiest to redrill the axles. I had to make changes to his approach to keep the calipers from interfering with the front sway bar and get the parking brakes (also C3) to work. But in the end I have very good brakes using parts that will likely always have replacement parts available

Do you if there were modifications made to make the C3 spindles bolt on to the Pontiac upper and lower control arms? Any issues with the steering setup?

The ball joint taper seems to be the same so that fit. If I remember correctly the C3 spindles are about 1 inch taller than the 61 Pontiac. To compensate my PO cut the springs 1 inch or more which was a bad move. The distance from the lower ball joint to the spindle center is the same on either spindle so no cut was necessary and I couldn't get my floor jack under the center of the cross member. About the first thing I did was put in new springs and the ride height returned to spec.
I also had to modify the C3 caliper mounts to put the caliper behind wheel center and not in front which was C3 style. Using the C3 steering arms makes my tire so close to the tie rod end that it limited my wheel backspace choice. But the car steers well and the tires seem to wear evenly. Although with the tall spindle it took a noticeable stack of shims to get the alignment set. It stops straight and quick so all is good.

i only upgraded the front to manual disk. the rear is still stock drum.
rears are an easy change to 5x4.75. i can order axles with what ever bolt pattern i want.
the front is a bit more difficult to change the bolt pattern.
my thought was instead of trying to change the front spindles and complete setup i would possibly re-drill the front rotors to change the pattern.
i agree that there are more choices out there now than when i started looking at wheels a couple years ago. but when you start getting very specific on wheels BP/width/offset the choices narrow down quiet a bit.

Might as well just get the rear axles and drums predrilled too.

I'm running 4.75" redrilled 69 Bonneville rotors, since the desired US Mags wheels were not offered in 5 x 5. Had it done by a local professional machinist, since accuracy is critical, and the back of the rotor must be spot faced for the press in lug bolts, which can be seen on the existing 5" pattern. Also, the bearing snout must be turned down slightly, since 4.75" wheels tend to have a smaller center hole. There is plenty of meat in a GM rotor for doing both operations, so no worries. One hassle, bought a dual lug pattern wheel for a spare tire!

There is another option, Scarebird offers a bearing spacer that allows use of 1LE 89-92 rotors, which are already 4.75". These will likely not have 1/2" lug bolts though, a quick check on Rockauto listed at least one rotor with metric lugs.
https://scarebird.com/index.php?rout...&search=indian
https://www.rockauto.com/en/moreinfo...sn=870&jsn=870