1990 vs 1991 Custom Cruiser Steel Wheels

I want to get a set of snow tires that can rotate between our 1990 CC and 1991 CC but not have to mount them every year. Is there any difference between the black steelies on a 90 vs a 91 other than the part number and maybe aesthetics that could derail this plan? I don't know which one I'll continue to daily drive in the future and since they use the same size 225/75-15 tires and 5x5 15x7 wheels I figure it won't matter much if I do this right.

Part Numbers:
1990 9590603
1991 9591768

Thanks

Check your bolt patterns. You can try mounting one of your spares on the other car.

I know they are both 5X5 bolt patterns.  I have a full size aluminum wheel on the spare in the 91.  I can try it on the 90.  I looked at pictures of the 91 steelie and the only difference I can see is the shape of the flat spots between the bolt holes. I don't have a 91 steelie since Bertha has the nicer aluminum wheels but Norman (our 90 CC) has wire wheel covers and steel wheels. It'll have to wait though, the 7" of snow needs to melt first!

If they both have 5 on 5, the wheels should be the same size. You can measure the back space on both to determine if the offset is the same.

They should fit. I remember that (in the 90's) we used my fathers 90 Chevy caprice Wagon wheels and wire wheelcovers on my mom's 91 Caprice. They fit OK!

I regularly swap rims on my OCC's. I have '77 OCC Custom Chromes on one of my '92's, '71 SSIV's on my 91, and Impala cop car rims on my '93 RMW.
The only thing to insure is to use GM full size car (B/C body) or C/K truck rims from a disc brake vehicle to insure no interference with the calipers in the front.

I'm going tomorrow to pull the rims off the old boxie CC in our yard. Same body style as our 90 only 9 years older.

Turns out the 91 OCCs aluminum wheels do not cross directly to the 90 OCC, the studs on the 90 are too short. I have to try the 81s wheels on the 91 tomorrow. Keeping my fingers crossed.

Wouldn't have thought the studs were the problem

Yeah, there's barely enough threads to start the nut and have any real hold.  On the other hand, I had the 1980-90 steel wheel on the 91 and it works just fine.

Replacing the studs is not a big issue. Tap the short ones out, and pull the longer ones in with a stack of washers, and a reversed nut.