I've been working on the Evil Step Dads 32 5w, and one of the things my Mom asked about was a heater. I think she was kidding but I took it serious. I had a spare 49 ford heater as a core, I removed the front cover and saved the rest for another day. For the fan I used this,,, http://www.svc.com/r4-svs-07ak-gp.html its an 8" 12 volt computor fan. Despite its appearence it doesnt move a lot of air so for a bigger car ya might look for something else. The original heater was nearly a foot thick, and by using this fan I was able to get it down to 5" The heater core is a random one of the shelf that would fit in the box, I'll get a part number tomorrow. I rerouted the inlets to feed into the bottom front of the box,, The relocated inlets now point directly at the heater control valve,, (again random off the shelf component, number tomorrow) which I mounted underneath. (warning the mexican alloy of aluminum and sand is a complete bitch to weld) the valve also serves as the bulkhead thru the firewall, and comes out just above the rear of the intake. For the defrogger I cut some 2" exhaust pipe and made a Y pipe, and then added a peak to make it not look like exhaust pipe. This was welded to the top of the case after cutting the proper shaped hole for it to breathe thru. I had a pair of defrogger vents leftover from an AC install last year that were slotted into the dash support. I had to make a new upper section for the dash andwhile I was at it I made up some louvers to cover the holes. Since the big fan doesnt move a lot of air I took a trip to Radioshack for a pair of 3" 12 volt computor fans. Made up a couple flanges and mounted them right at the end of the vents. Still have to work out the controls, they will be mounted to the bottom of the box and will cover the hose ends and inlets. Heres what you see with the dash installed,, not much of a tech I know but hopefully inspires some of you that are wanting a heater.