305 V8... 2 or 4 barrel carb?

[Pelon916]

Hey guys.. here goes another round of information leeching...

My truck has a 305 V8 with a 2 barrel carb (unknown make or model on the carb).
I don't know if the intake manifolds are stock, but I know they're nothing special either way, and they fit the small carb.

Anyway... I was offered a 600 cfm Edelbrock today and I'm not sure if it will help or hinder what I'd like to do with the truck.
I would like reasonably good gas mileage. I won't be towing much, if at all. I won't be driving the truck every day, so I don't mind swapping a little mpg for some hp. I also don't really hot rod at all.

Anyway... I guess I'm looking for opinions on the benefits of either a 2 barrel or 4 barrel on a 305.

Keep in mind that at the moment I have crappy stock exhaust manifolds, I will be switching them to ramhorn style soon.

If I put on the bigger carb will I most likely have to change the intake manifold or might it fit either size?

If I don't have nice exhaust yet will I not see a big difference until I get more flow on that end of the engine? I have dual exhaust now, and I plan on installing flowmasters when I change the exhaust manifolds.

Right now the truck has a 300 HP 283 cam but I don't know what valves it has or what the specifics of the cam are.

Um.. I dunno what else information might help me make a more informed choice about the carb.

The truck does run great at the moment, I'm just curious if a little more intake might help it run even better.

[cableguy0]

if i were you i would get a 4 bbl and get an edelbrock performer intake manifold you will pick up a few mpg. lots of people dont realize that a 4bbl will always have better gas mileage than a 2 barrel because with equal size (cfm) 2 and 4 barrel carbs the 4 barrel carb is using less fuel just driving around because of the smaller primaries. the gas mileage only decreases when you put your foot into it.

[Blue68]

Get the carb and a new/used intake. Pick a brand so long as it's made for lower rpm range and dual plenum. You will notice better performance even with stock manifolds, espcecially since you are running dual exhaust already. The 600 cfm is fine on a 305. Ran mine on a 307 for several years with no complaints. My only experience with a 2 barrel carb was the 30 yr old original that had a crappy rebuilt put in. Leaked and was so loose it was something that the engine ran.

Check the different parts boards. Also, check out swap meets for used ones. New ones can be had for around $120 from Summit.