So Ive had my 2001 Silverado for a couple years now((2001, 5.3 liter, LM7, Extended Cab ,LS , RWD), and about two months go, she threw a rod. After weighing my options I decided to find a used engine and swap it out myself. After about a months time of searching I found a gentleman online that was parting out his 2000 extended cab and along with it his 5.3 liter Vortec which ( I believe) was on a 4WD drivetrain. After extensively cleaning it and doing some other essentials (rear main seal, front seal, all gaskets and refurbished 862 heads) , I am finally ready to drop it in. But I seem to be running into some issues. Im doing all this pretty much by myself , but last night I had a family friend come through to help me mate the engine to my existing 4l60e, and after much nudging and cajoling, and even trying to "guide" the two surfaces together using some long bolts ran through the engine-to-transmission bolt holes, the friend gave up, saying hes done a few engine swaps, and hes never had one not just "come together" when the two devices were brought together. The friend says he has doubts as to the torque converter alignment in relation to the flywheel, and/or its compatibility with the donor engine. My question is this: Does anyone here know of any modifications required to make this swap succesful? Am i doing something wrong? Is there something im missing? The flywheel appears to have been installed correctly( convex going towards the transmission) , or do i simply need to keep shimmying and nudgin the old girl home? I hope the informatioin ive provided is helpful, sorry for the novel, and as always thanks so much for anyones feedback and insight......im so tired of not having my baby driveable....please help :/