385-SERIES BIG-BLOCK StrokersIf your objective is ground-pounding twist and shout, there's nothing quite like a big bore and long stroke to get the job done. The 385-series engine family can handle upward of 550 ci--given your budget, a custom crank, rods, and pistons. Because we understand the importance of budget for your mild-mannered street stormer, we're going to focus on affordable stroker performance.
Coast High Performance 501 ci
What About the FE?If your Mustang has an FE-series 390 or 428 Cobra Jet, you're likely wondering what's available to pump displacement into these classic big-blocks' time that the aftermarket seems to have forgotten. You can stroke a 390 High Performance using a 428 crankshaft to achieve 410 ci, just as Mercury did in 1966-'67. If your dear and late Uncle Ned left you boatloads of cash when he punched out recently, you can stroke the 427 block using a 428 crank to round up to 454 ci.
Because most FE blocks have experienced at least one rebuild in their service life, you can count on at least one overbore to 0.030 inch oversize. The FE big-blocks--except for the 427--will accept generous overbores up to 0.060-inch oversize. Because the 427 reaches the limits of the FE block with a 4.23-inch cylinder bore, the most they will accept is 0.020-0.030-inch oversize without flash floods. By the way, the 428 crank can be offset-ground to achieve a modest stroke increase.