I built a 318 last year for my 71 duster. I built the 318 because it was a low mileage engine but mainly because it was free and anything it better than the slant six. I didn't want to spend much money because I'm building a 528 hemi for my 66 belvedere and I just wanted a driver.
I did a stock rebuild. I was shocked when I saw how far the pistons set down in the block.
To make up for the low compression I advanced the mild cam 2 degrees from DTC. The 318 pulls real hard up thru 5000 and I have out run a stock 5.0. mustang. What more could I ask for from a stock 318 with a mild cam.
The key to making a 318 run decent is use a mild cam around (218 @50) and advance the cam a few degrees to build cylinder pressure at low RPM's.
I plan on building a 360 later but I'm very happy with the little 318 for now.
My car doesn't have power steering which helps the 318.