Ok, I've got a set of '87 350 heads just laying around and a comp cams 294 solid cam + solid lifters that have been setting around for close to a year. I was just thinking tonight, what if I were to put them on the 305? What would I have to do to make it work? Yes, crazy idea

 

You'd want to port the hell out of those heads. You would want to shave the heads as much as possible
to raise the compression ratio to a true 10:1. You would need better than stock springs with that .525" lift cam. You would have to check for any valve train interferance at full lift with that cam.
( retainer/ guide/ seal, rocker/ stud. You'd have to convert
to normal rockers/screw instuds with guideplates (not self aligning) for a solid lifter cam. That cam goes in at 106 intake centerline (4deg advanced) u'd want to experiment between 98 and 107 deg intake centerline to see what the motor likes.
You would want to use a single plane intake like a Victor Jr.
(port matched to your ported heads)
Long tube headers, free flowing dual exhaust and high gears 4.10+ and a 3500+ stall converter.
Were talking 8 3/4" or 9" behind a 305. Use a 750 cfm carb.
If you already have ".081" casting 305 heads, use them
with the above mods and big valves. They have as much potential
once ported. If those '87 heads are "swirl port" heads, throw 'em in the garbage. Do all this and you'll spank a few 350's for sure.

 

Hehehe dang, lotta work for doing something for $hits and giggles. I don't even know what heads I have on the 305 right now, I'm guessing the stockers from '82. Thanks for all the info though! maybe if I run into a chunk of change I'll do it just for the hell of it then drop in the BBC

 

good chance you'll get false knock counts with a solid cam and you need to consider valve to deck interferance and valve shroulding

 

Me no have no computer Anyway, I just wanted to see if it was possible. If I do the head swap, I'll probably just swap in a 268H cam. Had the 294S on ebay twice and no one seems to want to pay close to what I want for it.

 

The 82 should have the 416 castings. They can be made to perform, just ask F-BIRD'88 who has flow numbers for a ported set. Wow that's a lot of duration for a 305. It would be cool to see how the 305 acts with that cam.

 

With that much cam and using 350 heads you would be VERY prone to detoniation, due mostly to the large quench area you'd get using 350 heads.