89 Iroc conv

After I get the bugs worked out of my car I would like to up the power I have read that there was a 230 horse 305 in 89 it only came with a manual trans. What is the differnce between my 195 horse 305 tpi and the 230 horse 305. I would also like to install my hooker long tubes on the car but they don't have the air system will it or will it not work. I f the differnce between the two engines is the cam and I swap in the cam that makes the 35 xtra horse will I have to have to comp. reworked.

mdenz3

The AIR system only matters if you need it to pass inspection. I'm not sure about the other engine you mention, but if your going through the trouble of acam swap i'd go for a stock LT1 cam if i were you. Yes, you will need to reprogram the computer if you do a cam swap.

89 Iroc conv

I don't have to worry about passing any emissions. I to don't know which cam was used in the so called 230 horse 305I don't eve know if the cam made the power difference.To me a cam swap is simple I have been around mech. and body work all my life, but I have had no expirience with fuel injection so i don't know who or where to send my computer to reprogram it.

mdenz3

I belive most people on here use PCMforless who can be found in the supporting vendors area. If you look on Thirdgen.org there is a lot of info for modifing a TBI engine.

Marc 85Z28

While most of the power gain came from the camshaft, there were other changes made to reach that power level. The 89 you have is rated at 195, but the 230HP cars were later models that incorporated lighter pistons, dual catalytic converters, and were speed density (no MAF). All those in addition to the slightly hotter cam accounted for the 35HP difference.

Cam specs for 89 305 auto trans:
.350"/.384" lift, 179*/194* dur, 109LSA

Cam specs for 230HP 305:
.413"/.428" lift, 202*/207* dur, 114.5LSA

Edit: Do a little more research here and at www.thirdgen.org on why a cam swap should NOT be one of the first things you do. There is better power to be had elsewhere first. The cam will only realize any real benefits after the intake/exhaust manifolds have been addressed. Cam swaps on stock intake setups with poor flowing exhaust yield very poor results.