Possible turbo 318 build
I do not remember correctly, but I think you will get som issues with the converter? the 273 have too small center-hole in the back of the crank? or is this only if the crank has come from a stick trans?
500turbo-hp is doable on a stock 318 shortblock i believe! remember a turbo make the cylinder pressure furter down on the stroke, this is not stressing the piston and rod as much as a high output n\a engine who has the pressurepeak near tdc. you could also back of timing at the lower rpms (<4000rpm)to avoid the tq-peak early in the register that usually blow the shortblock in a turboengine....
the main rule is that a strong n\a engine needs less pressure to make great turbo-power compared to a low hp n\a engine with boost. this low-output engine have to work hard to get 500hp,while the high-output does not struggle to get a little more:-)
I'm sorry for my bad english ! hope you understand someting at least!
Turbo is underestimated!8) its CHEAP and easy power! at least if you can do something in the garage yourself!!