I run 26x7.50's. They have a section with of 6.3" and that is on a 4" measuring wheel.
Which ET Street? They make 4 different varieties including radials. THe only one worthy of true street use os the ET Street S/S.
While there is nothing wrong with bias ply tires, you do not ever want to mix the 2 together on a car.
It's good that it's been upgraded to 5x45.". That gives you nearly endless wheel options.
I run mine with those fronts on it and my wife has driven it many times. Honestly, unless you make some suspension and chassis changes It doesn't matter. I've never run out of front tire under braking or cornering but I don't corner the car hard. I just drive normal.
Being manual steering, a bigger front tire exacerbates the increased steering force required, albeit mostly at slower speeds. That is also something you can change in the future fairly easily.
There is definitely a difference in handling from 14's to 15's, 2 fold.. One is the very limited tire selection with 14". The 2nd is the increased sidewall height.
