1987 Dodge D150 pickup 5.2l 318 cid
I would simply build a mild stock stroke 318 with simple bolt ons such as 4 barrel carb and intake, headers and camshaft. The 318 is one hell of a truck engine. You will not be disappointed and you also won't be foolishly spending your money on a more race bred engine and you'll actually have a much better chance of finishing it to honor your grandfather.