I can empathize with you about putting projects on the back burner. Once done it is very hard to get them rolling again. I have a hot rod truck project I've been working on for 7 or 8 yrs. ('50 Ford F1 on an S10 Chassis, Corvette Independent rear, Lincoln 4.6 4 cam.) I keep towing it around, but I can't seem to work on it.
Your radiator/fan space issue is a deal breaker in my view. I saw an early p/u with a small block chevy once, it had the engine set back (hammered firewall) and electric fans. I can't imagine how poorly it cooled.