Sadly " Luck " plays a part in this ! Ive done plenty of race milage on 205 blocks with T34's at 2.2 bar and never had a problem ,
BUT ...
Add a T4 and its a completely different ballgame , they are the Terminator ,lol , and the first thing that goes is the Block between Cyl 3 & 4 , big splits ! Blew out my wire rings and lunched the lot , do you want to take that risk for a few extra quids worth of 200 block ????
And you know you will want more power, whatever you say now !
regards
Tony