Due to only finding limited posts for wheel/tire info for my 67'El Camino I have a question that might help a few other members besides myself. Are wheel/tire dimension the same for 64' thru 67'El Caminos and Chevelles? I read that the wheel wells for the Elky are slightly deeper and there may even be a difference in rear-end lenght.
Any help is appreciated.

Rear end length is the same for both cars but not 100% sure about fenderwell differences.

Dave,
I fit a 275/60-15 on a 15x8" wheel with a 4" back space EASILY on my '67 Elky. Plenty of room...
And '64 thru '67 rearends are all the same length; '68 thru '72 are about 1.5" longer than the earlier.

Not very scientific but I have both a 67 SS hardtop and a 67 Elky. I took the 15x8 (and 15x7) ARE Outlaw I's off the hardtop and put them on the Elky and there does seem to be a bit more fenderwell lip clearance on the Elky. The SS currently has 17x8 ARE 200S on the rear with 255/50x17 and 5" bs and maybe could have gone with either the 17x9.5's w/6.5" bs or a much larger tire such as a 275/50x17 - about 1" taller and 1/2" more sidewall...there's plenty of room on the SS.

The Elky's (and wagon) frame is longer than the hardtop but the wheelbase is the same. The extra length comes in after the centerline of the axle. Whether this gives more fenderwell room (at least front to back) isn't something I've ever measured.

As usual you guys are the top source of information for Chevelle/El Camino owners.
Thanks again.