Calipers are exactly the same.

It's an RS with the Z/28 RPO added. The P/O used all correct NOS Z/28 parts when he converted it back in the 80's. I probably have the GM receipts for the brake upgrades and will either look them up or will get you the caliper numbers with some pictures of the mods when I pull the front wheels to do the brakes in the next few days.

I'll measure the backspace as well for you but think it has 7's on the front and 8's on the rear. Again, I'll confirm in a couple days when I'm finished installing the new motor for it. Been thrashing on it for 5/6 days now and tomorrow the engine and transmission are finally going back in. :naughty:

Very much appreciate your trouble - mine is in storage for another couple of months until the weather gets decent so no rush obviously - but again Thanks for your offer of further info..
Randy

Not Americans but International Dragmasters from the 1960"s. [With ET center caps...]

These fit disc brakes without issue....

Those are cool looking wheels Jim.

Haven't forgotten about you on this, but not finished buttoning up some new mods here yet. I sent the rad out to be re-cored yesterday and should have it back and running in a couple days. I'll get to doing the brakes when it's running again and will get you some numbers. I did however look at the rims on the 68 car and it appears they are 15" x 7's all around and look to have 3.75 backspacing. It's hard to get an accurate measurement with the wheels still on the car so don't take that verbatim until I get around to pulling them later this week.

Cheers

Again I very much appreciate your trouble - but don't worry about any timeline on the info. My car has endured the stock rally-look for almost 50 years now and over 25 since I became the owner - a week, a month, or even a season works well for me.
Do it only as you get the opportunity and remember - but don't go to any extra trouble.. it is very thoughtful of you!

Part I - Rear Brakes & American TT Wheels

OK, found some time to check things out today as I was installing new shocks and trac bars and started pulling wheels to go through the brakes. So here are the details on the rear brakes and wheels. Rears are stock original drums #3841177 and no spacers were added using 15" x 7" wheels with 3.750 BS

http://i1218.photobucket.com/albums/...s/IMG_5010.jpg
Stock rear drums. No spacers required.

http://i1218.photobucket.com/albums/...s/IMG_5018.jpg
These American TT wheels fit great and look totally at home on a 68.

http://i1218.photobucket.com/albums/...s/IMG_5022.jpg
Wheels are 15" x 7" with 3.75" Backspacing.

http://i1218.photobucket.com/albums/...s/IMG_5013.jpg
Good inside clearance to shocks whether on stock shock plates or aftermarket trac bar applications.

Part II - Front Brakes & Wheels

I only checked one front caliper on passenger side and this car has Delco Morraine 4 piston caliper #5455946 which was an over the counter part to replace the original? I believe these were used on 67 & 68 Chevelle, GTO, Firebirds and differ only in part number from the 67 & 68 Camaro #5455530 & 5455533. There were no spacers on the fronts either. The front caliper/s had one embossed surface buzzed down slightly for the wheels to clear the caliper without the need for a spacer. I suppose you could use aluminum spacers but I've never been a fan of using wheel spacers myself. Mike at Western Corvette mounted these wheels for the P/O many years ago and this was commonly done on these cars to gain clearance for aftermarket wheels on 4 piston calipers. Pretty simple trick to mounting these wheels up. Front wheels match the rear and are also 15" x 7" with 3.750 BS

http://i1218.photobucket.com/albums/...s/IMG_4921.jpg
You can see the raised embossed area was ground slightly to allow the spokes to clear the calipers.

http://i1218.photobucket.com/albums/...s/IMG_4922.jpg
Close up showing the smooth part which has been ground slightly.

http://i1218.photobucket.com/albums/...s/IMG_5021.jpg
Here I am pointing to the area that was buzzed down with a rolox disc to gain clearance

http://i1218.photobucket.com/albums/...s/IMG_5022.jpg
Same wheels used front and rear. 15" x 7" TT with 3.750 backspacing

For those who like the stance on my 68, here are the tire sizes used. Front are BFG 215/65/R15 and the rears are BFG 255/60/R15 (all on 15x7 wheels as stated above)

I like original wheels too, but these work just great on these cars and they are cheap in comparison of costs or labour required to restore the often pitted originals. Use originals, repops, and use a 1/4" spacer up front if you like. Fact is they look right at home on these cars. Cheers

http://i1218.photobucket.com/albums/...s/IMG_4923.jpg

http://i1218.photobucket.com/albums/...s/IMG_4924.jpg