for the stock 305 what rang cam should i go for, will i have to put a bigger tb, sould i go with a 4.10

 

Do a search and see what cam other 305 owners are using.

 

With stock heads your pretty limited on a 'usable' cam range. Since the 305 is a low-end motor and you have a deep gearing, look at some cam sites like Comp or Crane and see their notes on the cams. They will tell you their range in RPM and where their suited performance is at. Low to mid range IMO is about what you should strive for. The TBI should be big enough right now. Also check to see what cam profile was on your year model. For instance the TPI 305 in 85 (1st year of TPI) had a better cam than the 86 motor. You may find a truck or another 305 cam that is cheap and will suit your needs. Look into heads too. World makes 305 SR Tourqers pretty cheap. SR means stock replacement, but they are a little better than stock And can be improved on as well. The stock heads on a 305 is a 58cc. Keep them 58 so your compression stays up there. When I still had my 305, I exhausted its limits of the stock heads/cam with everything else I could. Wasnt too bad, but it never would respond very well to all the mods like a 350

 

You can get a stock LT1 cam (around 0.450" lift) on ebay for cheap. I paid $40 for one with under 50k miles. That would be a great cam for a 305 w/ stock heads.