I'm late to the party here- - - -been on the road for a while! Ditto to all the above. The big outlet port and no heat riser is beneficial under heavy load, high RPM conditions when the engine needs to breathe freely. Unless you're spending lots of time at full throttle in the lower gears, the 250 manifold should work well. Another bit of trivia- - - -dyno tests tend to prove that too much exhaust pipe (like split manifolds and duals) actually reduces low-end torque. Maybe the engineers who designed the stock exhaust systems weren't dummies after all!
Speaking of exhaust heat- - - -Try running a big motorhome up a long, steep hill with the engine cover removed sometime. A Dodge 440 or a Chevy 454 will have the exhaust manifolds glowing cherry red and popping like popcorn!
Jerry
