Here is 2 other cool turbo 318s to get an idea of what you'll need to get the power you want.
68 Dodge Dart Turbo 318 Dyno Pull Mopar - YouTube
Stock 318 heads, exhaust manifolds, .467 Crane Cam, 904 auto, 13 lbs on Pump Gas, PT 67
397 RWHP 398 RWTQ, at Horsepower Ranch in Hobart Wa.
Twin...