I swapped in my spare 4.1 stroker engine this week to break it in and see if the ceramic coating from Swain Technologies on the used piston skirts would work. It works great. This engine has the ported irons, flat tappet cam, T&D rockers, and intake and carb off my 3.8. It's 9.5-1. It runs way better than the 3.8 due to more cubes, but no where near as good as my other 274" engine with the roller cam, 10.5-1, and GN1 heads. I think there is about a 50 HP difference. I plan to go through the 274 and put some moly rings in it and check the bearings. JE sold me hardened ductile iron rings for that engine because I use nitrous, and it has uneven compression and some blow by. Runs like a bat out of hell, but I think it can do better. I just need to recover from 2 days of wrenching. My old bones can't take it anymore.