So, I have been on this board for many years, asked many questions, received some great feedback and built my bird based on it all. I bought the car in '03 and as of today, 7/15/2017, I have less than one mile of street driving on the car. The motor started out as a 350 from something else, with a rod knock. Over the years while body and other work was being done to the car I have owned a 355 small block, a 455 030 over Pontiac, and where I am now. A 2003 LQ9 out of a '03 Silverado SS with a 4L80E. I recently moved to Illinois and no longer have a huge garage to work in, so the car has been in a shop in Northern IL for the last few months as I have moved, bought a place etc. I finally got to drive a mostly finished car today, and I will tell you, that thing is a BEAST! Far more than the old, worn out 350 that was in there and it has instant pedal response and shifts nice and crisp. The shop has to do some additional window alignment and install the windshield molding that they seem to have misplaced, so with any luck, she'll actually be in the garage next week.
The suspension is rebuilt stock with poly bushing, but I swapped out the springs for QA-1 coil overs and springs. With that combination I put a set of 225/45/18 wheels up front, and 255/45/18 in the back. I'm getting some fender rub up front, even though they've been slightly rolled, I think it may be hitting the wheel skirt bolt, so I am thinking about changing the front tires. The overall diameter for the fronts is 26", but I think it is the width, more than the diameter that is causing the problem. a 205/45 or a 215/45 are going to have a diameter of 25.26 and 25.62 respectively while the width would drop from 8.8~ to 8.4~ or 8.0~ respectively. I think the fronts are 18X8's, but it's been a few years so I don't remember. I also did see the attached link, but wonder what has worked for you guys.
1969 6.0 Firebird: project started (2/19/2014 LQ9 and 4L80E on the way) Information overload mode on this build 2013 Chevy Volt/2005 Ford F350 6.0 PSD CC 4x4 Lariat/2008 Honda Gold Wing Looking for 68-72 A body Wagon, prefer 70 Chevelle Wagon
Back spacing is going to make all the difference. I'm running 245/45/17 on 8" rims with 5.25" BS. Backs are fine of course but I'm running about a 3/8" spacer in the front( makes the BS about 4 7/8" or so) and I still get rub on the inside of the back of the tire on the subframe with the wheels cut hard over. I'll live with it. I just don't do that. Mines 69 so different shape openings from 7 or 8.