Your suggestion on how You would make this deal

[Bjj_junkie]

Current situation is that I found a good deal on a motor tranny combo. The engine is still in the truck but is ready to be pulled whenever deal is done. At the very moment I don't have where to store it but will in the next few weeks. I don't wanna risk losing it to another buyer so the seller suggested doing a partial payment and he could hold it for me for up to a month and then once i have the space I can give him the remaining money and take the motor. The guy seems like a clean family oriented blue collar dude but I still feel weird handing someone money with nothing in return and just trusting a stranger. How would you deal with this situation? Thanks