Did the 4v engines have larger valves, or different heads in anyway, over the 2v. Im asking because i want to put a 4 barrel on it, and dont want to do it and just be wasting gas. Thanks

 

Which engine?

 

I assume you are talking about 351c engines. There are several differences in 351C 2v and 4v heads. Intake and exhaust runner sizes, valve sizes, and cumbustion chambers are all different. If you are just looking to upgrade to a 4 barrel Carb you do not need to change the heads, just the intake manifold. Several comapanies make 4 barrel carb intake manifolds for 351c with 2v heads. I have an Edelbrock preformer manifold on my 351c 2v with an Edelbrock 1405 600CFM 4 barrel carb.

 

Man, Im sorry, im talking about the 289's in 66.

 

and again, i know that if you have small valves, and you stick a big 4 barrel on it, you'll just be wasting alot of gas, and not really getting any performance out of it.