I own a 1993 GMC 5.0 liter and I installed a spacer under the throttle body. I also have my own repair shop and that has proven to be the best thing I could have done for performance and mileage. Jegs and Summit both sell the spacer.
The engine
Well, you have to replace the heads with a carbureted head, but why would you want to? Fuel injection is a much better system, especially if you're trying to modify an engine to get more power and better performance out of it.
You should replace the head gasket. This repair is critical to the better performance of the vehicle, and to prevent future damage of the engine.
They each have several engines available. My vote goes to the Chevrolet small block.
The 1960 Impala had different engine size that had a big influence on performance. The top dog was the 350hp 3-2barrel 348cubic inch engine. With that motor it had very good performance for the time.
A chevvy big block engine is a powerful, high performance engine that is installed in large trucks. Example of trucks that have chevvy big block engines include the Chevrolet Corvette and the Chevrolet Nova.
The 350 was first installed in the 1967 Camaro as a performance option. The rest of the car lines in Chevrolet received the engine over the next couple of years. Nova got it in 1968.
One can purchase a big engine from the following sources: Engine First Limited, Engine Factory, eBay Motors, Big Engine, Chevrolet Performance, to name a few.
Allows the engine to breath better.
model year and engine size are relevant to the question.
Replace the ignition wires.
Trouble code P0410 means: Secondary AIR System Performance