Some will disagree, but for a stock replacement your local auto supply can often be the lowest cost alternative. For example, a long block for your '93 C1500 from O'Reilly's comes with a 3 year, unlimited miles warranty - PowerTorque Remanufactured VCM5 - Long Block Engine | O'Reilly Auto Parts

You might also look at national places like Jasper's, but I think they may only sell through their installer shops, local independent mechanic shops who buy from them wholesale, have tax numbers, etc, etc. My Son-In-Law bought one from them recently (without talking to me first......) Just a thought, trying to offer you some alternatives.