I would go with the kit no major clearnce issues you can use the stock 5.7 rods or 6 if you like. Is the block early or late (2 pice or 1 pice rear main seal. IMO use the Scat crank. My 383 I have Scat crank and rods www.ScatCrankshafts.com and KB hyper pistons United Engine and Machine Co, the places you will have to check will be the pan rail area for the bottom end of the rod, the rod bolt at the cam. Any good machine shop can do the clearnce work as part of the prep work for a stroker. A 4.0 bore and 3.75 stroke 377/ 4.030 , 3.75 383 and so on. Hope this helps Dave