Doc replied: 401's are out there but usually a fair amount of money. On the other hand 360's are just as good a choice. I had a friend with a Spirit with a stock 360 from a jeep an it was quite fast. He used to surprize quite a few on them Ricers. That's the car that had the free flows on it. "Doc" Good advise. I get people asking me DAILY about building a engine, what should they drop in? I have for years told them a 360. The 390 was only pressed from 68-70 and is virtually impossible to find parts for 33-36 years later. The 401 enjoyed a life from 71-80 in AMC, Jeep and International Harvester, but is also hard to come by; you might try some of the 'tips' on finding engines on my Shut Up & Drive Lists with the ads, but any salvage yard that has a IH with 401 is happy to sell anything off it. Usually you can get a running 401 for under $500, and if you find one at a Pick A Part, any AMC engine is $89, 401s included. www.houstonpickapart.com remember,YOU have to pull it, they will not ship, nor will they tell you what is in the yard as they don't know with 1500+ cars in there. YES, AMC made a forged steel crank (not cast) for 360. They are damned near next to impossible to find, only used 1-2 years. And yes, a forged steel crank was also made for 290/343 series. I don't believe I have ever had one in stock in 20 years a vendor. Here was my auction from recently with some numbers ya'll might wish to save for later: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2197679547&ssPageName=ADM E:B:EOAS:US:3 Hi Tom Cloud, nice to see you here. Now back to whoever is considering the engine swap. If your car is running and driving fine now, leave it alone. You can 'locate' and 'build' a engine in your garage or wherever for another day. And for what it is worth, if speed is the issue here, the aMC 258-6 backed up with a 904/998 series trannie is a formidable setup. There is a LOT of speed equipment available for the 258! Try some of those websites on my Planet Houston Vendors Lists. Four Wheel Drive Hardware, Edelbrock, Cliffords, Sharps Supply a few come to mind. Any of ya'll ever seen Ed Fernandez' six cylinder Gremlin turning 11 second 1/4 miles? Bring your bad ass AMC V8 over here and let him whip you like a scared schoolgirl with TWO LESS cylinders. And I want to add that there are same, if not more performance parts available for the 904/998 light duty Torqueflite than is for the heavier 727. My 68 Rebel convertible 'Machine' http://www.ep.com/pic3/1424121/1025056734463.jpg has a LAPD 401 Interceptor with a 904 behind it. Many people like these as they wind up real quick! And if I didn't think it could handle 350+ hp I wouldn't have put it in there......127,000 miles ago. So if you haven't made up your mind yet, (and there is some good opinions her eon this subject from ya'll) stick with the 6: easy to find parts for, many performance items available, dependable and hard to tear up; or if you must go with a V8, consider a 360V8 for the reasons mentioned above. All in all it will come down to your financials, expertise with that engine (AMC or not), and what type of driving you wish to do when finished! Don't forget the main goal of having fun! And good luck with your project. Eddie Stakes' Planet Houston AMX www.planethoustonamx.com