I spent hours researching new rims so thought I'd post what I found here, I only looked for rims under $200 each that gave a muscle car look.

Cheap (not custom offset) rims will almost always require spacers to get your tire outer edge to sit stock so I opened up the search to 5x4.5" bolt pattern rims also since the adapters can change the bolt pattern.

Firebirds with 16x8 wheels have the tire sidewall sit about 1/4" outside of the outer front fender (245/50/16)
and about 5/8" inside the outer lip of the rear fender (255/50/16).
This is what I measured on my 16" gold lace TTA and used in my spacer calculations below.

FORD BOLT PATTERN
Wheelreplica.com

REAR 05-12 Bullitt or Cobra wheel 18x10 $145 free shipping
45mm offset 7.2"BS, needs a 1" ford to gm adapter, outer edge of rim will sit same as stock 16x8 wheel. Will clear fender lip. Can use a 1.25" spacer to increase inner fender clearance but will be close to outer fender lip. May need minor hammering and removal of rear bump stop

FRONT 05-12 Bullitt or Cobra wheel 18x9 $144 free shipping
36mm offset 6.4"BS, needs a a 1.25-1.5" ford to gm adapter, will sit like stock, no rubbing

You can buy the 4 GM to Ford adapters on ebay for $100, total cost is about $700.

GM BOLT PATTERN
Amazon.com

REAR Torq Thrust m 17x10.5 $163
44mm offset, needs a 1" spacer to sit near stock on the outer edge.
This give 6.5" BS, which will require major inner fender work.
FRONT Torq Thrust m 17x9 $154
45mm offset, needs a 1.75" spacer to sit like stock on the outer edge.
This gives a 5" BS, which has no issues

You need to buy 4 adapters on ebay for $100, total cost is about $750.

firstchoicewheelsandtires.com

Mickey Thompson SC-5 18x10.5 $248 (above my budget but it's soo nice)
54mm offsetn 7.88"BS, needs a 1.25" ford to gm adapter to sit near stock on the outer edge.
This give 6.63" BS, which will require major inner fender work.
Mickey Thompson SC-5 18x9 $233
32mm offset 6.25"BS, needs a a 1.25" ford to gm adapter, will sit like stock, no rubbing

You can buy the 4 GM to Ford adapters on ebay for $100, total cost is about $1075.

TIRES
Sumitomo HTR Z III 295/30/18 and 265/35/18 $692 shipped from tirerack.com


Decisions, decisions.....

 

I'm going to suggest that you put some more money towards tires - Sumitomos are not know for being good performers.

 

Agreed, but the HTR Z III seems to have stepped up from the prior versions:

http://www.tirerack.com/tires/tests/...&affiliate=AH8

I'm also looking at EVO 12s or Vredsteins for a bit more coin.

 

Putting it this way, tires are the interface that connects your car to the road. If you have a tire which features an aggressive, sticky design, your car will perform much better than a more pedestrian design meant for more pedestrian use. Since you are going to purchase wheels and adapters anyway, why not get the most bang for your buck performance-wise and get those aggressive tires from the start.

I know you are in bad weather absent San Diego, so why not go for something $100 - $150 more a set and reap all the advantages a wider wheel and tire can give. BFG G-Force sports, Dunlop, Nitto, and Falken all make super excellent (but affordable) tires that will be 2 or 3 steps up from the Sumitomos or Vredsteins in performance...

 

Thanks Paul -

I ended up going with the Torq Thrust M 18x10 and 18x9. Total cost $712 via Amazon
For tires I got Bridgestone S-04 285/35/18 and 265/35/18. Total cost $900 via Tirerack

I was going to get 255s for the front then I read your other post about our cars being front heavy so I reduced the stagger.

I'm currently running a 315/35/17 on back and 275/40/17 on front (Nitto R) and it really doesn't understeer too bad now, but going with the 285 265 combo should reduce it a little further.

 

Post pics when they are mounted up!