my 305 has a 520 lift cam with 184 valves,i have asked three people for advice they say change cam to a smaller lift you will increase power! my cam's duration i dont know but it sucks most of the vaccum from my brake booster! and im convinced to go from a th350 to a 700r4 since i went from 2.29 gears to 3.23 i think i have more gear than torque so at 3000rpms my engine is screaming

 

Either change your cam or change your rear end gears. Cam is too big for your application, your engine will be a total dog until you get it up to 3000 rpm or better.

 

i will change cam and see if there is a difference

 

Yeah, cam is big! How come you know the lift, but don't know the duration?
Wana keep the cam? and the TH350? Change the torque converter! A 3000 stall converter will put you in the power range right off the line! But with the 3:23's you'll need a tranny cooler around town because the converter will be slipping in city traffic unless you drive around in second gear under 60 mph. 3:42's will help that some. A vaccum canister resivor will help with the power brakes and you can raise the idle rpm with the higher stall speed converter without the tranny slaming into gear or stalling at a traffic light.