Farmerdick,

I'm new to this site but I'm also working on 1940 Chevy Coupe Special Deluxe. I've had it since Christmas of 2013. So far I have finished the chassis. I'm using a Heidt IFS with Chassis Engineering motor and trans mounts and radiator mount. I was also using their leaf spring rear suspension but they couldn't ship the springs on time and we went with a Possie rear spring setup. The chassis worked out well.
I bought a mock-up plastic motor from P-Ayr. This was about a $450 investment when you add the timing cover, balancer, oil pan and other minor items. It has saved a lot of back problems trying to locate engine mounts and trans cross members. I hope to be finished with it as soon as I get to the stage where I can mount the body back onto the chassis. I'll put in up for sale and try to get a little bit of my investment back. I'm using a 700R4 overdrive trans and I got a used case only from a local re-builder for $50 to use in the mock-up. I'll trade the case in when I buy the rebuilt 700R4.
Based on the mock-up and talking to several people that have built this car the 350 SBC will fit with the standard firewall. You can use a below the floor or a firewall mount brake master. Be careful with the front
acces. drive setup you use. There's enough room up front but not enough to be wasteful. I've seem several BBC installations and they do get rather tight in places.
Hope this helps. Let me know if you have any other questions. I'll try and help.
PS: I used Yogi's for my primary supplier. Ask for Nate!