I own a 77 el camino. When i bought it, it had a 305 with a 2 barrel carb. Recently, i removed the engine and put in a 350 from a 72 chevelle. With the upgraded motor, i decided to up the carb to a 4 barrel. With everything installed, the engine runs good, idles fine, but it doesn't seem to shift correctly. Since then i have heard many explainations, from the tranny is blown to the engine is bad. but most recently i have heard that the carb is to new for the tranny and the way it shifts the engine is different (something to do with vacuums or cables). Has anyone heard of this and if so could you give me some advice? Rsponss are appreciated

 

Normal shifts (regurlar throttle)are......first shift 12mph - 15mph .....2nd shift is 23mph - 27mph and 3rd is 33mph - 36mph generally. Check the vacuum line coming from the Vacuum Modulator if there is transmission fluid in that line the modulator is bad and needs to be replaced. If the transmission fluid is bad it will shift at different points also.If the engine is built you might need a different modulator than stock but if its a regular 350 engine the stock one will work fine. So start at the vacuum modulator first since its only like 10 bucks.

 

Did the old carb have a cable from the accelerator linkage to the tranny. Or connected to the butterfly. If it does its the kickdown and probably just needs adjusted.
And whoever told you your carb was to new dosen't know what they are talking about.