how can i beef up my 318 performance

360 is a great choice, but if you already have the 318 and want to work with it, they have a lot of potential. This is the age long argument here. Although the Ford guys don't throw away ALL there 302's in the fox bodies for 351's or stroker 347's, and yet they make them 5.0's fly (and love 'em).... Us mopar folks (commonly speaking) throw away the 318's. Of course 340/360's offer more upfront, but in no wise does this mean the 318 can't get it done. A four inch crank in a .030 over teen is about 400 cubic inches.... and plenty of guys have done this and gone 10's in street cars.