Try asking dis guy...he's my idol thus far
Perodua Musang 850EX (850 Turbo)
His engine specs taken frm the website...
friendly and very generous in giving advices...I'm also embarking on dis project next year...not extreme as he is...going stock turbo only...
one more thing...what kind of 850cc engine are u using? izzit ED-10 carburator? then I supposed you can use wif L200s head...and the block is pretty strong to withstand 1bar ++
if you're using ED-DE Twin Cam Injection like I am (Kancil Auto 850EZi lampu bulat...same as kelisa 850cc)...better using L7 head since it's DOHC...and the block is not that strong...that's why I'm targetting stock turbo and boost settings
Good Luck bro....