I recently purchased a 772 replacement fan off of eBay that was listed as the correct replacement for a 69-70 SS Chevelle. When I removed my old "racing fan" I discovered that the new aluminum bladed clutch fan would not fit within my shroud. The cooling fan is 19" in diameter and comes above the radiator like a table saw. I may have the incorrect shroud or the fan may be incorrect. Can someone help me out with this?
The fan is on great shape but I can't use it if it won't fit the application.
It may be that I just need a new shroud? Any input would be appreciated.

A GM 772 should fit properly in a big block fan shroud. That's the fan I'm using along with a Hayden fan clutch. Lot's of others using that combo as well. Do you have a big block fan shroud? How about motor mounts? Some guys say their engine sits too high when using the 307 frame mounts and engine mounts.

The car is all original numbers matching SS 396. I don;t think the motor mounts have ever been messed with. I'm hoping it is the fan shroud.
Does your fan shroud come above the radiator deck?
I took the old fan off about 20 years ago when I was young and dumb (er). I know the fan shroud is not the original one but not sure if it is the right one. Like I said, the 19" fan comes above the radiator top deck by about and inch. This wouldn't be an issue if it were covered by the shroud but without it, it's a frickin' table saw. Is your 772 a 19" fan? Thanks

1970 B.B. Trivia. A org. (curved tip 3947772 blade) is very close to 18 1/4" Dia. The Org. B.B. fan shroud stands 1" inch above the 4 bolt Rad. hold down plate.
The 307 SB. fan blades have a larger Dia. 19" PLUS. Dia. Why the difference in Dia. The centerline of the water pump. Also the ORG. 772 fan blades have curved tips, WHY ?
A Org. 394772 ( curved tip) blade matches the inside radius of the Org. plastic shroud and will not hit the inside of the Org. shroud under a torque load.
B.B. = 18" blade, S B = 19" blade. I hope this info helps.
Bob ACES-AACA

1970 B.B. Trivia. A org. (curved tip 3947772 blade) is very close to 18 1/4" Dia. The Org. B.B. fan shroud stands 1" inch above the 4 bolt Rad. hold down plate.
The 307 SB. fan blades have a larger Dia. 19" PLUS. Dia. Why the difference in Dia. The centerline of the water pump. Also the ORG. 772 fan blades have curved tips, WHY ?
A Org. 394772 ( curved tip) blade matches the inside radius of the Org. plastic shroud and will not hit the inside of the Org. shroud under a torque load.
B.B. = 18" blade, S B = 19" blade. I hope this info helps.
Bob ACES-AACA
Thanks, that answers everything. They sold me a small block clutch fan. Nice.
Thanks for the knowledge and the response.

A GM 772 should fit properly in a big block fan shroud. That's the fan I'm using along with a Hayden fan clutch. Lot's of others using that combo as well. Do you have a big block fan shroud? How about motor mounts? Some guys say their engine sits too high when using the 307 frame mounts and engine mounts.

Hank,
Please help me figure out which fan and clutch to buy and where to buy it.
69 SS 396 stock shroud.
Can you supply me with part numbers for the clutch and the fan so it's not so confusing?
Do I buy from GM Parts Direct? I am not so worried about being perfectly original, I just want it to cool.
Damn, it's frustrating !!!!
So far I am hearing a GM # 772 for the fan and #88961767 for the clutch. Is that the setup I need?
Thanks bro,
Randy

The fan on my 70 SS 454 Sta. Wgn. is the 3947772. The clutch I am using is not a cheep one. It is from a Chevy Dealer I was screwing around trying to keep my wagon with a 468 KOOL with the A/C running.
I will tell you what clutch I am using. It bolts directly to the 3947772 fan blade. The clutch is for a late 80s- 454 Suburban with dual A/C units. If you are interested I will find the G.M. part number. IT aint CHEEP but it WORKS. $133.00 at a Chevy Dealership On a hot day with the A/C on in my 468 wagon the temp in TRAFFIC will go to 220 that is OK.
Bob

Bob,
If you wouldn't mind, I would really appreciate the extra effort.
Price is fine, whatever it is. I just want it to run cooler so I can drive it without worrying so much.
Thank you,
Randy

Randy, the 772 fan was used from at least 69 > 73, maybe more years, so there should be plenty around. Don't know if GM Parts Direct has them or not. Check Ebay and craigslist, don't pay a premium for a date coded one. Mine was made in 73 and cost around $60 on Ebay a couple of years ago.

The Hayden 2747 is a HD thermostatic clutch and a good choice. Stay away from a severe duty, they're designed for trucks or other extreme cases. The 2747 is plenty and won't be spinning like crazy when you're cruising on the freeway. This combo kept my 396 and now my 454 under 200* even when stopped idling in traffic in the summer.