I was under the assumption that all z28s came with a 305 HO-I was checking out the exhaust system and it does not look like a 21/2 inch pipe feeding the muffler-hence the possibility of it not being an HO-i wanted to change to a performance muffler without changing everything-the dynomax book states that the HO has this size-how do i tell what motor is in the car?

It all depends on the year, I believe. You are referring to the 3rd gen Camaro's, which are the ones that sported the 305, and it varies greatly from 1982 onward. In 1986, I think you had several options, including 2 carb models, and a TPI model. I am not certain what the HO would be, but the TPI made the most power. As for the exhaust, I think it is safe to assume that the exhaust has been changed at least once since 1986, and it is always possible that a smaller pipe was put on.

[This message has been edited by BreathWeapon (edited 11-19-2001).]

If I remember correctly, there were two versions of the 305 that were offered in my 84 Z28 (not sure if this holds true in 86). One version was around 175 HP and the other was around 195 HP. The 305 was the only engine available with the 5 speed. In 85 they started putting the 350 back in but it was only available with the automatic trans.

I think you actually can tell which 305 from the vin. I vaguely remember one being an H the other a G. A shop manual like Chiltons will help you decode. Also the emmissions sticker on the fan shroud might tell you too - if it is still in place and intact.

[This message has been edited by Eric68 (edited 11-20-2001).]