hello, ive searched for a while on the boards but for some reason i cant find this even though it seems to me like a question that would have been asked before lol

when replacing a 305 to 350HO vortec motor... if the 305's pump is in fine condition, do you need to replace the water pump? or are all small block pumps the same.. no matter the displacement or power of the motor etc. is it really required?

sorry if the question was asked before, but please lead me in the right direction

 

most of the sbc water pumps are the same, there are however some reverse rotation pumps out there for the serpentine belt system. if you are sure the pump you have is good and the rotation is correct then I don't see any problem with reusing it. if your motor is of the higher output variety you may want to consider on of the high flow pumps just because our cars have trouble getting enough air flow and tend to run hot.

 

Amen, get a high flow unit. With a good motor why screw around with a stock pump.

 

Find out from the motor manuf. what kind of watre pump is req. True, on the serpentine belt, the pump has to be rvs rotation. So going from the 305 to 350 should not make any difference is what style pump.

But, get a flashlight and look at the underside of your pump from under your car. There is a little hole about dead center behind where the pulley attaches. The 'weep' hole. If you see stains from coolant leakage from this hole, its time for a replacment anyway.

I got a alum/ hi-flow water pump from edelbrock (@ Year One). Works great. And since you are getting a 350, prob worth the $$.