AFR suggest you use 205 for the 428.unless you are running a lot of compression and RPM. And they are not in production yet 4-6 weeks at best for delivery.Mine is 11.5-1 solid roller 246-254 626-647,standard shift 3.91 gear and they still say use the 205, better velocity, so more response and tourqe on the low end. This is if it is a street car.If it is race only it may be different.I ordered the 225 anyway
. May change my mind before it is to late...we will see.