no vav advance.could it need better gas.it has speed pro forged alu pistons.i think 10.6-10.7 and i dont know how much the block was decked.my uncle had my engine done for me at the machine shop and he would not let me see the receipt because he did it as a gift and didn't tell me how much he spent,but the receipt was about 2 or 3 feet long.the reason i think it might need better gas is i usually mix 110 with my 93 and here lately i haven't put any 110 in it.