Question: are ls main bolts tty?
Answer: Which LS Fasteners are TTY? On a GM LS engine, the cylinder head bolts are TTY and cannot be re-used. The connecting rod bolts are also TTY, but can be tightened up to three times for bearing checking. ... The vertical main bolts can also be re-used, but the side bolts are often replaced because they have sealant on them.