Alright guys I need some information. I've searched and read as much as I could on here but I'm about as confused now as when I started. This is what I'm going to do. I'm on a budget but do have a little money to spend.I have a '91 bird with the LO3. I have a set of Vortec heads off of a 350, I've read so many different things about these that I don't know what's what. Can I use these heads on my 305, I'm planning on using the valves in the heads, but I want to machine them so I can get more lift. Will the valves clear the 305's bores? I don't plan on doing anything to the bottom end of engine, how much will I have to have the heads milled, and what gasket do I use to get me to about 9-9.4:1 compression? I'm going to be using an Edelbrock vortec style intake and about a 650cfm carb, I'm doing away with the tbi. I also need to if my 91 LO3 is hyd. roller or not? So i can order the right cam. currently I have som Hooker 2055's on the way and a cat-back. and a K&N open element filter. Please try not to confuse me more than I am . Thanks guys.

 

If it is the original engine, then you should have a roller cam in it. As for the valves, if the heads came off of a 350 then you are going to have to cut out the block to accept the valve travel. Another difference in the vortec is the intake bolt pattern. So, when getting the intake, make sure you get one for vortecs. Oh yeah, if you don't want to loose compression, mill the heads to 58cc. That is all I have right now
FBird

 

I'll agree with milling the heads, but there won't be any valve to cylinder wall clearance issues.

Have the intake manifold milled as well so you won't have any leakage issues.