I'm wanting to change my 65 Starfire from 5x5" bolt pattern to 5x4 3/4" for more wheel options. Has anyone else done this? Did you replace or re-drill the rear axle shafts? I would appreciate any info on what parts you used, replacement axle shafts and front hubs. Any info would be helpful.

 

Welcome. In '65 there were pretty much 2 classes of Oldsmobile's: A Bodies (called "Intermediates") and the B,C Bodies (full-size - aka Starfires/88's/98's). These days we call the B,C body cars "big cars" here since they're longer, weigh more, are wider and have larger parts than the A body Cutlass/442 models which share a lot of parts with other GM A bodies like the Chevelle, Skylark, Tempest/GTO, etc.

What you're asking for is 100% rational from a parts-availability standpoint, but for a "big car" Cutlass parts are generally a safety downgrade. The big cars used the 5x5 pattern for a reason - at least weight, size, wheelbase & width. If you really want to put 5x4.75" wheels on in a factory kind of way, have a look at 65-66 Jetstar 88 parts. That car was a hybrid of Cutlass suspension & brake parts in a big body car. Olds did this as a price cutting option, not really a safety option. Those "hybrid Cutlass-Big Car" parts are pretty rare these days.

An Alternative
In 2025, when everything around you has disk brakes & ABS, do you really want to make your car harder to stop? With less brake swept area from parts designed for the Cutlass/442 as opposed the larger heavier "big cars"?

Over the years GM made many wheels that were 5x5. Chevy trucks leap to mind. I think some police cars too. Others here know more than me.

I'm running 15x8 wheels on my '66 Starfire & have converted it to dual master cylinder with front disk brakes in a nod to safety. Joe P has a long running thread on this conversion. Dig around here and you'll find some alternatives to using Cutlass safety parts on a big car.

65-66 Starfires can gain a great deal of safety by upgrading to front disk brake, a dual master cylinder & wider wheels, but it's some hunting & some work. At the extreme end you can custom machine 2003 Caddy rotors to fit the 5x5 pattern since original Olds late 60's rotors are thin on the ground. I did that, but admit it's an extreme solution.

The 65-66 big cars are not easy to restore/maintain. Part of the fun is the treasure hunt, at least to me. There's very little you can find for them in catalogs, they're just not popular enough to warrant much aftermarket support. That makes the restoration hill a lot steeper to climb. Here & there you'll find some Cutlass trim, or Impala, or Grand Prix parts that fit, but that's good fortune, not by design.

Please don't interpret any of this as a knock, just telling you what I've learned over 40 years or so with a couple '66 big Olds. Sooner or later you'll drive family & friends in your fun old car, I recommend you make it as safe as you can before they get in.

Above all, welcome aboard, you'll find a lot of knowledge on this forum. Any & all questions welcome from here.

Cheers
Chris

 

These cars used the larger bolt pattern for a reason. They are heavy. The smaller pattern has less load carrying capacity. There are plenty of 5x5" aftermarket wheels. I have a set of American Racing TTOs on my 67 Delta. You'll spend a LOT of money to change the bolt pattern then you'll have problems finding brake drums that fit. Don't do it. Just get the right wheels.

 

a 65 would look nice on a set of poly cast ssiv wheels.

 

The poly cast wheels are a fine design, but you’d still wind up with a cool looking less safe car. Same with the SSI’s. There was a time when I might have made that trade off, but it’s in my past.

Where I sit now @60 ~almost 61 years of age is there are a many wheel designs which look great/interesting on these old cars.

These days I wouldn’t trade safety for a wheel look, especially with the multitude of full size 5x5 wheels in widths from 7” to probably 12” widths available.

Part of the fun is taking family/friend for a ride. Keeping them as safe as can be is where I aim.

Cheers
Chris

 

I thought the SSIV Polycast wheels were 5x5 bolt pattern, so they should be a great choice.

 

You may be quite right if the poly cast were from the late 70’s.

I recall seeing them look great on 88’s from around that period and GM had definitely gone to bigger wheels and tires by then.

In the 60’s 5x4.75” was the rule for the intermediates, and 5x5 was the rule for the big cars.

 

SSIV polycast wheels were only offered on the 1971-72 Delta 88s and only came in the 5 x 5" bolt pattern.

 

I went to look at a 65 Starfire local to me a month ago . It had polycast wheels painted black. It looked pretty good. Probably look better in original grey though