Anybody know how I choose the right belt tensioner for my friends 93' silverado 1500 c/k 4.3L

The ACDELCO10229114GM Original Equipment says "EXCEPT Off-Road Air Cleaner (9K3)"
The other is just ACDELCO38108{#88909598}Gold / Professional

Pulley center bore is diff between the two..

He does not have a K&N intake, just a regular intake...

Also, sorry to get off topic, but I don't want to start a new thread...
In Virginia...
Should he use 5W30 or 10W30 oil?

Anybody have a clue which one is correct for a standard replacement part?
I'd hate to have to buy both, then send back the incorrect one...

If it doesn't have a special off-roading package it is probably the first one.

Regarding the oil: Personally if it has a lot of miles on it, I'd go with 10W30. What does the oil cap (and/or owner'* manual) say?

4.3'* hold up well with whatever the factory recommends.

Also, how many miles does it have on it?

It doesn't have the off road package...

Next time I see him I'll look at mileage and the oil cap, pretty sure its miles are up there...
Truck runs good to be so old, I got to drive it a bit..