You said, you wanted to replace your " worn out" 318... is the block bad? An old casting like that should have thicker walls. Seen a few 318s bored for 4" pistons...which makes things cheaper/ easier to find.
Worn out is wrong word.
Engine was bored and rebuilt but the cooling jackets were improperly cleaned. Example, Core plug above starter rotted thru after 10 years and 29K miles. Example, coolant filed with sealant.
Lots of little things done wrong.
Don't confidence in this motor.
Gas mileage is poor.
Cylinder walls look OK.
I just don't want to invest money into a 318 when I really want a big block.
If the car has to be off the road a few months, I don't give a damn.
I'm going to scrap the magnum idea. Thanks everyone for their input! Ben