b20 - boosted is a NO GO ... it has week sleeves ... but i have a b18b1 longblock for sale if he jus wants to swap out the motor and the b18b1 head flows better than the B18a1 ,, im letting it go for CHEAP ... so if he jus wants to put in a lil better motor hit me up .if you want to boost a motor .... b18a1/b1 is the way to go !