What is your goal with the car once that engine is in? Are you worried about traction? If so I wouldn't want to rely on the stock IRS if you are going to be drag racing it a lot. Sure there are mark viiis that have been 10s on the basically stock IRS but I believe with different half shafts and center section..but who's to say how long that'll hold up..if its just going to be a fast street car then that should suffice. Drag radials on the street with that much power aren't going to hook hard enough to break anything..in fact they will probably spin more than hook, at the drag strip with a prepped track surface, that's another story. On the street you won't notice a difference between a 335 drag radial and say a 295 or 315. If you just want the look of a 12" wide rim on that big of a DR then that's one thing, but not necessary for traction. You could make a 315 DR with a 10" wide wheel work just as well. This would still probably require slight modificafion to fit and the proper wheel offset. Go bigger on the sidewall height rather than overall tire width..more give in the sidewall will help with traction also.
