Either pump will work, straight arm or bent arm.
Point the Arm towards the bottom of the Pan, then level it off, push Pump onto the block, Then screw in the first Bolt by hand then the second one. Then snug them down.
You want the Arm under the Cam.
The Pump I bought, made in Korea, the holes in the Gasket were too small for the Bolts. I used a HF Hole punch to make them the right size.
I used some Permatex brown goop and glued the gasket to the Pump. Lined it up and shoved it into place.
I came in from the top side to replace it, I read you can do it from under the truck.
Disconnect your Batteries first
Remove the Alternator and set aside
Lift out the vac pump with hose and set aside
Remove the big bracket the Fuel Filter bolt to and set aside
You will have to disconnect the hard Fuel line to between the pump and filter and remove.
Cut the rubber curly Q hose in 2.
Remove the 2 bolts that hold the pump in, and lift out the old pump.
Shove a rag into the hole and clean off the area of grease/dirt etc...
I eliminated the hard line,and used rubber hose to the Filter. Screw in a barb fitting into the pump and filter head.
Use 3/8" hose.
Attach new pump
then bolt on all the parts removed to get to the pump.
Remove the Filter off the big bracket to make it easier to bolt it back on, just 2 bolts.
Replace the curly Q hose and the rubber hose to the filter or the factory hard line if you want to keep it. But remember the hard line has those Olive seals that will probably need replacing.
I filled the rubber hose with ATF before attaching to the Filter to eliminate any air getting into the system.
As I remember you need to tighten the Alt belt first before the Vac belt.
Connect batteries and hope for the best.
I replaced my Lift Pump because it was leaking out the bottom of it.
When I drove the truck the first time, it really had more acceleration. I guess the old Pump was not supplying enough pressure.
Goat.