91 V2500 Suburban - fan sits completely behind shroud opening, which part is wrong?

[gmbellew]

max mode only changes to recirculation mode. if going to max mode also changes where the air comes from, there is a vacuum hose hooked up wrong in the controls. you could pull the controls ans check how it is hooked up there. but the mistake could be at the vacuum servos, in which case it might take somw trial and error to swap the hoses at the controls to get it right. the hoses are color coded.

 

[bucket]

That's a typical radiator and shroud for a big block rig. I like the add-on ring... simple and effective.

 

[chris3353]

First post here, apologies if this belongs in a different section - mods feel free to move it.

91 V2500 Suburban 4WD, 5.7 TBI, factory front + rear AC (still on R12, recently confirmed pressures etc). Cools fine at highway speed, but at idle the AC gets warm and coolant temp creeps. Both recover once moving, so I went chasing idle airflow.

Done so far: new Hayden 2784 clutch (catalog correct - problem existed before the swap too), cleaned the condenser/radiator gap. Hosing the condenser at idle drops temps immediately, so it's airflow, not charge.

The issue that I believe is the culprit: the fan blade sits entirely BEHIND the shroud opening, not half in/half out (photo attached). Paper test confirms it's pulling air from around the shroud at idle instead of through the core. All the shroud mounting hardware looks stock (I think?). Radiator is aftermarket (previous owner), water pump history unknown. So something in the stack is a wrong part pretending to be stock.

Questions:

1. Water pump hub projection - anyone have the spec (gasket face to clutch mounting face) for the 87-91 R/V pump? Ever seen a replacement pump with a shorter hub pull the fan back out of the shroud?
2. Shroud variants - small block uppers came as 14021283 (no AC) and 14021285 (with AC). Is the AC upper meaningfully deeper? Would a non-AC upper on an AC truck leave the fan behind the opening like this?
3. What's the correct fan blade for an AC/HD 5.7 R/V truck, and do replacement blades vary in dish enough to move the blade plane an inch+?
4. Anything else that sets fan fore/aft position on these?

Planning to measure hub projection and pull the molded shroud number tomorrow if I can, but figured I'd ask before ordering parts. Thanks!

You must be registered for see images attach

One more just for fun:

You must be registered for see images attach

Your shroud is incorrect. IF you have not sourced a new one i can snap a pic for you later today? Maybe you have the BBC shroud

 

[winfred]

that shroud looks like my 78 big block c30, here's my 91 v2500 350 burb shroud strapped to the big block radiator o'reilly sold me as a "heavy duty" years ago

You must be registered for see images attach

You must be registered for see images attach

 

[guyindallas]

Nice to know that it can fit! Does it bolt up correctly?

I did order a standard shroud to replace my temporary aluminum fix, though it would probably continue working.