The 250 responds pretty well to a few conventional go-fast tricks, cam, compression, and some moderate port and valve work. If you can get by without going to multiple carburetion, so much the better. While two or three carbs look sexy on a show truck, they're just twice or three times the trouble unless you plan to do nothing but run wide open all the time.
One sneaky trick is to replace the dish-top 250 pistons with flat-tops for a 307 V-8. They're the same bore size, weight, compression distance and wrist pin size, literally a drop-in swap. They raise the compression about one full ratio. Combining that swap with milling .050" off the head will get you another .25 ratio change or so. The ones I've built that way didn't need any milling for piston-to-valve clearance, But I didn't go radical on the camshaft timing or lift. If you decide to cam it up, by all means check for adequate valve clearance. There is a 4-barrel intake available, but don't go overboard on CFM capacity. Too big a carb will destroy the low end and midrange torque pretty decisively. There are split manifolds available for dual exhausts, which make it sound better, and might even gain a little HP at high speed. Nothing beats cubic inches, so a 292 is the best way to make an inline-six-powered Chevy turn some heads!
Jerry
