I can't say that I've worked with any yet, (TA block) not sure I'm really comfortable with them either. Since there has been nothing but hype and little or no actual use of them, I still prefer the BMS stage 2 blocks as a platform. I know they can handle the horse power. I had considered trying an aluminum block but didn't want to be a guinie pig for that kind of money. It would be nice if we could have been given some first hand info and details of any true testing of the block in action, actually being run in a car. It just hasn't happened, have heard conflicting rumors, but thats all.
To sum it up, I know I can make 1000 to 1200 hp with a S2 block and live. If your interested in that level of performance, I know what I would suggest......
