Switching to 5x4 3/4 Lug pattern on a 71'
 

2 questions on this....do you guys know if there are any rotors that will swap over from a car? Someone told me that mid 70's Bonneville rotors will work.

Also, I'm wondering if axles from a Chevelle 12-bolt might happen to be the right length to swap the rears with the truck 12-bolt? I happen to have a set in the garage.

I have a set of GM Ralleys, and I'd like to put them on the 71'....just wondering what is commonly used to convert from 5x5 to 5x4 3/4.

Thanks!

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

http://www.jegs.com/webapp/wcs/store...egory_rn=36674 At the rear, you can redrill the axles & drums, or opt for a car (complete diff), & weld the brackets on to fit it, but I doubt you will get any stock car type axle shafts to slide in. up front, I had heard(but can not confirm) that some of the early 70's Vans used a 4 3/4" pattern. The tough part is when you can get the 5 on 5 wheels for around $60 a pop, its probably the most cost effective way to go. Best of luck.....crazyL

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

I was about to say that crazy... you can get stock looking corvette rally wheels in 5 on 5, and even in 6 lug.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

WHY would you want to go to the passenger car wheel lug pattern? If you have a truck, and you use it like a truck is intended, why go with less stopping power?

If it is for the wheels, I'm agreeing with Longhorn Man.....there's lots of wheels out there that are made for the 5-lug pattern. For those who have a 6-lug truck, like mine, there's more than I could choose from....with spacer/adapters, the late-model wheels can be used.

I just got my 6-lug, Corvette-style rallye wheels back from the powder coaters, and they look great, and they're 6-lug. With a cap and a trim ring, they're way cool.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

less stopping power?????? im gonna run a 5 on 4 3/4 and use c5 corvette brakes and 13in rotors, and thats way more stopping power. i m going that route cause all the performance stuff is mostly 5 on 4 3/4

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

The Chevelle axle swap will not work. The axle bearing & surface in the 12 bolt truck rear is much larger than Chevelle, Camaro, and Nova. The Impala's used a big bearing like the truck, but also 5 on 5 bolt patterns as well.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

Okay, you win!!

I don't have the imagination, nor the unobtainium (money) to fund such an upgrade. Yeah, you'll have more stopping power. No argument. I just thought, maybe because of others wording, that the upgrade was to use passenger car, not 'Vette, components. Go for it.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

Does anyone know if the early van small bolt pattern was only on drum or is it possible they had disc. I wonder if it would be the same bearing.
Tommy

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

My 1972 Chevy 1/2 ton van has the disc-brake 5 on 4 3/4 lug pattern. Think they changed to 5 on 5 in 73, but not positive.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

Thanks Livewire, I go to the parts house and do some comparing, I will let you know what I find.

Tommy

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

If you want to go do a complete C5 brake conversion that's fine and I'm sure the stopping power will be fantastic but Rreemo originally asked about rotors and rear axles for his '71 so he could mount his 4 3/4 bolt pattern Ralley wheels.

I checked a few things and find that both the C10 and G10 (van) use the same outer wheel bearing but they use a different inner bearing and seal, probably Impala size and smaller than the C10.

I looked up a 1975 Bonneville, which was still one of the really large ones, and found that both the inner and outer wheel bearings and the seal are the same as 1971 C10. So if you can confirm that the Bonne is 4 3/4 then you need to confirm that the diameter, rotor thickness and offset are the same. These specs must be the same or it won't fit your caliper location which can't be changed without swapping in another spindle.

They should both look the same laying side by side except the bolt circle. NAPA shows 3 different grades of Bonne rotors. A cheapo replacement for $41.; a premium one for $73.; and a high performance rotor for $114. It looks like you are on to something here.

Redrilling your rears is absolutely the easiest and cheapest way to go. Any machine shop can do it by drilling the 4 3/4 pattern between the old 5" holes. This is a common practice in street rodding. You could even do it at home if you have a good drill press and some carbon drills.

Of course the easiest way is to sell those 4 3/4 Ralleys and buy a set of truck bolt pattern Corvette Ralleys in a 5x5 pattern. That's what I'm using on my truck and like was said above they are about $60. each from Stockton Wheel or House of Wheels.

I guess it's up to you how much work you want to do. If you could find good used Bonne rotors (no newer than '76) you could probably come out cheaper all together.

Tom

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

The only reason I was considering this is b/c I already have a nice set of Ralleys in the garage...so if I could've used the axles that I also already have, all I would've needed would be some rotors....just a different lug pattern, not any smaller in over diameter, thickness, etc.....wouldn't make any change what-so-ever to the stopping power of the truck.

I wouldn't think it would change the carrying capacity at all either, but that's a non-concern for me as well....this truck is being restored, no plans at all to be used as a work truck....I leave that duty up to my F250.

BTW - BIG thanks to everyone else for the replies on this...I'm going to look into the few options I have here, but it appears that it might be worth it to just sell the Ralleys that I already have, and then buy the 5-on-5's from someone like Jegs, since they are pretty cheap.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

Good info Tom, thanks a bunch! Just one other question for you....do you know if the 5x5 pattern Ralleys (like you mentioned above) will accept the smaller disc brake center cap? I want to use the smaller style cap...not the sombrero style.

Thanks again!

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

I bought my Vette-style Rallye wheels from Summitt Racing....free shipping. The wheels are from Wheels Vintiques and are the same price I would have paid for them, from Wheels Vintiques. But, the shipping from CA to AR, would have been $85. So, buying them from Summitt was good for me, plus I got the center caps and hot-rod style trim rings, not the ones we're used to seeing on Rallye wheels. I took 'em and had 'em powder-coated in red, but they come with a silver powder coat, that had some trash in the finish. My powder coater guy smoothed them out and then sprayed them.

Honestly, I think you'll be better off in the long run to go with new wheels for your truck, and sell your old Rallye wheels for whatever you can get for them (but don't give them away!). It is my opinion, that to convert to the smaller lug pattern would be a bit of trouble. The comment about the Pontiac wheels didn't say what the pattern was, but Pontiac, Olds, Buick and Cadillac all used the 5 on 5-inch bolt pattern, while Chevy didn't go to that until they changed up the trucks in '73.

Re: Switching to 5x4 3/4 Lug pattern on a 71'
 

Yes. The GM disc brake caps work on these. You can use the bigger '68 and up hats or the smaller and nicer looking '67 style. You can also use the police caps which I have or the ones that wheel companies sell that are the same but without the Chevy bow tie. There are also smooth baby moons, a '49 Chevy cap a '52 Chevy cap and a '56 Chevy cap made for these ralley wheels.

Tom