HI Bruce - great to see this puppy back out of the pound! Give me a holla when you do the V20 - no room in life for big models these days, for sure
There's a 4*20E not far from where I type that was lucky to get built without a fair amount of cribbing
Firewall move vs spacers? An electrocution of a kit like this one, it's probably easier and stronger to use the slimey firewall and some spacers. My favourites are as many Liteply discs as are needed, on account of they're easily made, cheap and I don't have to find them, order them and wait around for delivery...
A custom electric power model will have the firewall up back of a typical outrunner these days. Why mess with spacers when placing the firewall properly will do the job better, lighter and cheaper?