crate engine suggestions

[lifted k10]

hey guys I have a 2wd 86 stepside, sm465 truck with a $6,000.00 budget for a new engine. Im torn between the year one aluminum headed power crate 350, gm performance parts zz4 or gm performance parts fast burn 385. This truck is not a high rpm race machine and will be used as a cruiser and to tow my bass boat around. Im also planning on keeping the stock sm465 transmission for the time being. Let me hear ur thought's on helping me pick an engine.