lift pumps

[odee]

I'm gonna have to replace my lift pump soon on my 87 sub. The later models up to 91 use a different lift pump is it any better than the 87 model one?

[odee]

can someone give me a suggestion to this because I don't want to spend money on one to find out the later style is better.

[gmctd]

Emissions standards had been further tightened by '91, and is more than likely the reason for the different numbers. Not to mention the metric standard, applicable to fuel lines, as well.
Have the parts man bring you one of each year pump, compare inlet to inlet, outlet to outlet.
Check tube fitting threads, noting if flare or o-ring type seal.
Flare was inch, o-ring is metric. The trucks were a little late getting the full metrric treatment.

Other than that, the mechanical interface is the same.

jd

[odee]

thanks if I remember right I had a older guy tell me that the later ones had a check valve in the pump to keep it from losing its prime.