My brother in law has a 1995 5.7 complete long block with 135k. Used no oil but had piston slap for a few seconds upon cranking. Its been in a shop about three years. I have a 1999 Suburban with 183K and have high oil consumption. I understand I can use the block but need to get vortec heads and then use my original fuel injection set up. I plan on useing this to tow a trailer and would like to modify it a little for better towing . Has anyone done this swap?