espada

Hi guys, i need some advice regarding Lc135.. Is it ok to have a 63mm block with big racing superhead i think 30mm while just using a stock exhaust? Because i have tried a leovince sbk exhaust and it feels stuck and the bike couldnt go.. i have stock exhaust and im wondering if it is able to...

Just asking for opinions from you guys. I currently now using lc135 standard block. Im thinking to upgrade it to 62mm. But the issue is which brand is actually good and dont burn a whole in my pocket which can withstand a long period of usage without giving a headache ? Maybe Espada ? Cms ...