Tire Questions

[xs29bb1]

Hi guys -

I'm going to be putting Red Lines w/ Mag 500s on my 68 R/T restoration.  I was thinking going with 235s up front and 275s in the rear  (My wheels are 15x7 in the front and 15x8 in the back)  Coker has a max width of
235 I think, so they're not going to work. 

I looked at Diamond Back - they have a few choices of 60R15s in the widths I want, but I believe they actually cut the tires to insert the read lines which voids the warranty on the tires.  If anyone has used these guys
before I have a few questions:

1.  With the tires being cut, do these tires lose any strength?  (i.e. are they safe for heavy driving?)
2.  Does Diamond Back put any kind of warranty on them?
3.  How do they look?
4.  Are they a good deal, or there someone else who does a better job/has a better price?
5.  They have a few different tires to choose from - any preferences?

Any help appreciated.