mechanical vs electric fuel pump?

[12B]

I noticed on my newly acquired '70 K5 that it had the standard mechanical fuel pump next to the engine as well as an inline electric pump next to the filter attached to the frame under the RR fender well. With the standard 350 V-8 and 4bbl Holley I wouldn't think 2 pumps were necessary. Is this someone's backyard project or factory? Any advantages/disadvantages to this? Also, the manual says this engine came with 2 different Holley carbs -- the 4150 and 4160. I can't find any ID tag. Any physical distinction?

 

[R72K5]

rochester and carter were only carbs that came light duty trucks in the 70s

electric pump has no reason to be on a carbed vehicle, only need about 7psi to run a carb just like what mechanical pumps deliver

i would go get a new stock pump for 70 k5 350 and put that on, sounds liek you got some previous moron owner correction work ahead of you

good luck

 

[TONYP]

R72K5 is right, the electric could damage the seals on your carb...the stock pumps don't even have a return line to the tank...