need help identifying what cooling fan came on my bbc

[atowley]

Hi guys! I am working on an old rv, its a 1983 chevy class a with a 454. I built the engine and it dynoed at 400hp but i now need a fan to cool it. From what i have found online a 7 blade 19 inch mechanical fan is about the largest gm fan that was offered, but i cant find the application where they used these fans. Its part number 3999260. Thanks for the help! And if anyone has one that would work i certainly would be interested!

[nvrenuf]

There are also differences in fan clutches too; standard, heavy duty & severe duty. The true severe duty is only available in a BBC truck with 4.56 gears.

An 83 K30 3+3 w/ 454, 4spd and 4.56 gears will have both the severe duty fan clutch and a 7 blade fan.

[tucsonjwt]

Now that you are no longer have a stock engine, I don't think you will find an exact match anywhere in GM parts listings. I have a stock C20 with a GM Goodwrench rebuilt 454 and 4:10 rear axle. I replaced the fan clutch with an AC Delco from a catalog search and it works fine. I kept the stock fan. The C20 is a camper special.

I would just go with the standard 454 fan and clutch and if it won't cool enough you can add an electric fan. The electric fan will help cool your A/C condenser. I got a fan out of a Geo Metro because it was the only one which would fit, since one side of the radiator was blocked by the factory oil cooler. The Metro fan is wired with a relay to the A/C compressor, so it turns on when the A/C is turned on.

[atowley]

Any idea what fan they used on a 454? Part numberwise

[nvrenuf]

I thought already had a part number but now wanted an application?

[enaberif]

Originally Posted by atowley

Any idea what fan they used on a 454? Part numberwise

There were 3 fans types used.. 3, 5, and a 7 blade with 3 various types of fan cluthes.. normal, heavy and sever duty.

More fan blades != better cooling. There are too many things that are in play including the radiator in use.

Unless your truck is overheating I wouldn't worry about it.

[tucsonjwt]

My 454 fan is about 18 1/2" diameter with 3.25" bolt pattern (rough measurements) and has 7 blades. It has some numbers stamped on it but I can't find those numbers online - probably obsolete: A83 140 15666 (the last 3 numbers are difficult to read - may be "8" or "9".) I am guessing that this is a severe duty fan - my truck is a camper special.

My truck stays at 160 degrees according to the stock temperature gauge in 110 degree desert heat in the summer.

I see big block 7 blade fans for sale on ebay. I would get a good used oem fan over an aftermarket fan. It looks like these 7 blade fans are pricey. I know the Delco fan clutch cost me over $100 from an OEM online retailer (I think oehq or oe warehouse.)