No... not that kind of engine. I've been looking for a either a 401 or a 425 nailhead for a couple weeks now. I called a guy that had a pair of 425's with transmissions for 1 grand each. I called and got him down to $800 on one of them until he told me that one was seized. I told him I wasn't interested and he then told me he would sell me the other one for $800. Then he proceeds to tell me that it has 750 some odd hours on the engine as it was used in a starter cart for aircraft. He then tells me that these engines were used in a starter cart to start the SR71 Blackbird. Who knows if this is true... I asked for some sort of verification and he said he would work on getting some pictures of the cart he had laying around with one of the engines still in it. I looked on line and it appears that nailheads were used for this but they all say 401's were used. Beyond the possible history I'm wondering if anyone knows if there are any differences in engine output when they are used for an industrial application or if they just grab one off the assembly line and use it for their needs. If these truely came from the background he is explaining they didn't use any sort of exhaust on the engines... I'm assuming after 750 hours of run time that the valves and seats may see some damage. The engines have an original 4 bbl intake and carb and I believe they were rated at 340 or 360 hp. Any input is welcome.