Expert: Matt Lyons - 9/21/2007

Question
i want to do a few minor upgrades to the 305 in my 93 caprice. the engine has 170 HP and about 250 torque stock.

i was thinking easy stuff like exhaust, intake, pulleys, spacers. however as the most radical upgrade i wanted to go with an intake/ throttlebody upgrade. but i am not sure if it will make a big difference at this power level.

furthermore i would like to get headers installed on this vehicle and make the mostly legal. but i read another article/ posting that says i wold have a true dual system.

how much should a true true dual system with bigger pipes affect the low-end toruque and hp?

Answer
The 305 motor isn't really a performance based motor. It is basically used for daily passenger/commuter type cars. You can, however, do some things to pep it up! I would start by changing to a cold air induction system. This allows the engine to breathe better and not draw air from the hot engine compartment. Cool dense air = more power. Next I would look for a throttle body spacer and injector spacer. This moves the torque curve and also removes restrictions from the airway. Now you have more air coming in you need a way to get it out.
I would look for headers that replace the stock exhaust manifolds. Edelbrock is one company you could try. Follow this up with a free flow catalytic converter and a cat back exhaust system from Dynomax. I would normally recommend Flowmaster but their mufflers are just too loud for the street. Changing the pulleys will reduce parasitic drag but will also affect your cooling and charging systems.
I have done most of these mods on my own 95 GMC 1500 with a 305 and have seen night and day differences. You may also look into the B&M shift controller that controls torque converter lockup. It installs with two wires on the computer and makes a hell of a difference.
Hope that answered your questions. You can also post questions on my website:www.lyonsperformance.com
Thanks