Engine Change Out Ford 390 (1935 Ford)

I just purchased a 1935 Ford 5 Window and I need to change out the engine. The vehicle came with a 390 V-8, 427 Crank, and 427 Heads. The block has been bored out too far already so I need to purchase another engine. I definately do not want to change out the headers as they have been custom made for the vehicle. What do you suggest? I am trying to keep the costs down but still get a good engine. I have a Holly 4 barrel Carb. and it has a 4 speed trans.
Do you know someone who has the right engine and I can just put it in. I can purchase a Ford 390 running from a local junk yard that is guaranteed to run for $450 ( but then I am not sure what I am getting).
Any and all help is appreciated.Need your expert advise. Thanks, Richard L.

If the carb is on the motor, wire the throttle blades open for the compression check.

Can you not afford to rebuild? I know we're not all made of money but I've had me nightmares with used engines and I can just bet that changing the engine in your '35 might not be a walk in the park if the nose of the car is fully dressed. I'd hate to see you stuff it in and a year or so later repeating the process when that engine gives up the gusto.
I'm willing to bet you could get a rebuilt shortblock done for around $550-650 or so as long as your heads are in good shape. This would include a good replacement core shortblock you could put your rotating assembly into.
Not sure on the cost, but you could also possibly sleeve the existing block you already have and start over with standard size pistons. It's a frequent practice with 427 blocks as they are short comming and getting more expensive.
Keeping those 427 heads in play would be the best idea as most 360-390 heads are slugs and just don't hold a slice of bread compared to the 427 heads. Furthermore, depending on which 427 head you have may dictate whether or not the 4bbl intake you have will work on another replacement FE's heads you might pickup.

Just some food for thought.