What you gain in rotor diameter, you loose with caliper clamping force with the C5 brake conversion.
The Blazer caliper has 1.81" diameter pistons versus the Corvette's 1.59" diameter pistons. In the braking world, this is a huge difference in clamping force. To match the clamping force of the Blazer calipers, you would have to increase the size of the vacuum booster (easier solution) or reduce the master cylinder bore diameter down to 7/8". A 7/8" bore master cylinder may be impractical with the angle of a g-body firewall. There are not a lot of 7/8" bore master cylinder options that work with the g-body angle.
A better choice, in my opinion, with a C5 brake conversion is to use a 1998-2002 Camaro/Firebird caliper that has 1.77" diameter pistons. They say there is more caliper flex over the Corvette caliper, but it is more likely from the larger clamping forces created from the F-body caliper's larger pistons. If you have a C5 brake conversion already, you will notice the difference in braking performance going to a 1998-2002 F-body caliper.
If you do NOT have brake fade, you do NOT need larger rotors. If you DO have brake fade, this can be mitigated with a more aggressive pad that works better in higher heat, but you may loose some streetability with a more aggressive pads. A more aggressive pad is a much cheaper route than a C5 brake conversion. Streetability will depend on the pad you choose and the type of driving you do.
The C5 brake conversion looks great in an open spoke wheel. If you do want to go that route, buy the 17" wheels you want first that will work with the C5 brake conversion with a 1998-2002 F-body caliper. Granted the F-body caliper is not as good looking. The 17" wheels, more than likely, will work with the Blazer brake setup you have now.
