how to build engine with big shorrock

[pimp incher too]

is here somebody that tryed this before? i want to make 30hp engine with c142b shorrock,the only thing is that i am afraid thet the studs come out the engine or that the cilinders get broken. how can i make this much stronger? the engine has now 87mm pistons and big bore 356 cilinders. the cilinders are very close to the studs,they are now from 356 becouse the original don't fit with these cilinders. somebody?