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Hi I'm Mike and on this installment of Summit Racing Quick Flicks we are going to talk about
the differences between Chevy V8 water pumps. One of the questions we commonly get is what
water pump is right for my Chevy V8 whether it be a small block or big block Chevy. The
reason for this is, Chevy developed two different type water pumps for these engine types a
short type and a long type. Physically looking at these pumps a lot of times when they are
mounted on the engine it is difficult to tell which version you have on your engine. So
today we are going to go ahead and discuss the differences between the pumps and how
to determine which pump you actually have installed on your engine so when you actually
go to replace this pump, you order the correct one. So how do you go about determining which
version you have on y our engine. Well usually I will just take a tape measure and take a
measurement from the mounting *** to the hub surface of the pump your typical long
version pump will be six and seven eight inches tall from that to the hub surface where is
in compression your short pump will be roughly five and five eights from the mounting service
to the hub surface. Now there was a year split between the years in which these pumps were
used, the short pump was used most commonly on 1968 and earlier applications and the long
pump was used on 1969 and later applications the thing about this is you cannot guarantee
the one or the other is going to hold true to your specific vehicle. Reason being a lot
of engine swaps have happened over the years where they have taken complete engines including
the accessory drives and all of the components that go with that and swapped them into early
model vehicles or vice versa. So it's really best to confirm which version is on your application
via taking a measurement or physically looking at the pump and determining which one your
vehicle has on it. Now the one exception to the year break rule is the corvette. Corvette
applications held on to the short type water pump for a much longer period in fact it carried
on to the point which they quit using belt driven water pumps. In those cases it is not
really possible to switch to a long pump in a corvette application because of radiator
clearance issues, the radiator is a lot closer the engine in a corvette in comparison to
your standard Camaro or truck application. So make sure if you do have a corvette and
doing an engine swap that you go ahead and swap over the proper accessories as well from
the original motor because if you don't the long water pump that is on that later
model motor that maybe you are putting in there may not work with that engine compartment
set up. The last thing you need to consider before selecting the proper pump for your
application is your snout diameter, this right here; the snout can affect the way your pulleys
fit as well as the way your fan assembly fits. GM used two different versions, they used
five eights which is the most common and they also used the heavy duty version which three
quarters inch. Make sure you confirm which one your vehicle had before selecting the
proper pump for your vehicle. There is another way you can determine which pump you have
just by taking a visual inspection of the engine. You can see here how the gap in between
the pump and the block is very narrow, this typically indicates that you have a short
type pump on your engine assembly in comparison on a long water pump application there will
be a much larger gap between the pump and the block assembly to the extent you can almost
fit your hand in-between the two.