51 flathead. what would you pay?

I don't know if this is the right spot for this question, but here goes. i bought a 51 ford to do over.It's all together and looks cool now but I'm doing it over any way(chop is a must). It has the original flathead V8 with three on the tree. The engine looks runs and sounds good and has dual 2bbls on it that are both hooked up. I'm going to pull the motor and trans to do a 350/350 swap. I want to sell the flathead and trans but I really don't know what it's worth. I don't want to ask to much but I don't want to rip myself off either and any money I get for it would go into the new drivetrain. so my question is whats a running, good looking flathead V8 worth on the market? Thanks guys.

 

surely someone will trade you straight up for the 350/350 you're looking for