Complete '71 318/904 Combo - NorCali

Hey all,
Its in my 71 Valiant right now. Runs...but probably needs a tune up. Gas thats in the tank is probably the biggest reason it doesnt run great. Its a complete setup with the 904. Dont know any history of either. Motor is original, factory A/C and 2bbl. Asking $400...I am in needing a bare block though, to use for mock-up. Maybe a partial trade of some sort?
If interested, let me know. Thanks a bunch!