Backspacing and drum brakes question

[Josh69]

I've read so many posts, I can't keep it all straight.

I'd like to put some 18" wheels on my '69 firebird, but I can't afford to put 4 wheel discs on it just yet. I assume that a disc conversion (I'll be doing a stock type disc setup for street, this isn't a track car) will increase each side by about 1/4"?

If so, I'll order my wheels as if I'm doing discs, then use some 1/4" spacers until I get the discs.

I'm thinking 18x8 fronts with ?? backspacing, and 18x9.5 rears with 5.5" backspacing. I am welding new quarters and wheelhouses in it shorty, so I can roll them before paint if necessary. Probably 245 or 255's in front and 275 or 285's out back.

Any advice?

[Hammered]

It probably depends on the rotor. I'm putting LS1 rear discs on mine and the difference between the rotor and drum thickness is only 1/8" per side.

[Josh69]

They are having a sale on Centerline Meteors, nearly half price per wheel, so I wanted to order them before Monday....but I just can't bring myself to do it until the quarters are on and the brakes are in....I guess it pays to measure twice and order once!

Such a good deal though......